The political uses of astrology: predicting the illness and death of princes, kings and popes in the Italian Renaissance

The political uses of astrology: predicting the illness and death of princes, kings and popes in the Italian Renaissance

Studies in History and Philosophy of Biological and Biomedical Sciences 41 (2010) 135–145 Contents lists available at ScienceDirect Studies in Histo...

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Studies in History and Philosophy of Biological and Biomedical Sciences 41 (2010) 135–145

Contents lists available at ScienceDirect

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The political uses of astrology: predicting the illness and death of princes, kings and popes in the Italian Renaissance Monica Azzolini School of History, Classics & Archaeology, University of Edinburgh, William Robertson Building, 50 George Square, Edinburgh EH8 9JY, UK

a r t i c l e Keywords: Italian Renaissance Astrology Diplomacy Politics Prognostication Death

i n f o

a b s t r a c t This paper examines the production and circulation of astrological prognostications regarding the illness and death of kings, princes, and popes in the Italian Renaissance (ca. 1470–1630). The distribution and consumption of this type of astrological information was often closely linked to the specific political situation in which they were produced. Depending on the astrological techniques used (prorogations, interrogations, or annual revolutions), and the media in which they appeared (private letters or printed prognostica) these prognostications fulfilled different functions in the information economy of Renaissance Italy. Some were used to legitimise the rule of a political leader, others to do just the opposite. Astrological prorogations and interrogations were often used to plan military and political strategies in case of the illness or death of a political leader, while astrological prognostications were generally written to promote certain political leaders while undermining others. While certainly often partisan to this game, astrologers, for their part, worked within a very well established tradition that gave authority to their forecasts. This paper argues that, as indicators of deeper political tensions otherwise not always explicitly manifest, these prognostications are privileged sources of information providing a better understanding of the political history of the period. Ó 2010 Elsevier Ltd. All rights reserved.

When citing this paper, please use the full journal title Studies in History and Philosophy of Biological and Biomedical Sciences

1. Introduction In the letter addressed to the student of astrology that opened his widely popular Christian astrology, the seventeenth-century English astrologer William Lilly gave a stern warning to those learning from his books: ‘Give not judgment of the death of thy Prince’.1 The message was clear: predicting the death of powerful people was a risky business. Lilly’s cautionary message had an ancient pedigree. From classical times to Lilly’s own century, examples abounded of how astrologers had suffered at the hands of their lords because they had made unfavourable predictions.2 As Hilary Carey poignantly highlighted, it was this type of astrological practice that

had contributed to the ruin of astrology’s reputation in England in the late Middle Ages. The unsavoury association of astrology and sorcery in this period seems to have discouraged its overt use. A spate of cases where courtiers had attempted to predict the death of Kings Henry V and Henry VI had made astrology unwelcome at the English court, and legislation was soon implemented to make it an offence to try to predict the death of the king by any form of divination.3 The following century witnessed a more cautious and circumspect use of astrology at court, and it was only with the rise of the printing press that astrology flourished again fully in England.4 Like many of his fellow Renaissance practitioners, Lilly, however, did not quite practice what he preached: in the 1640s he published a series of

E-mail address: [email protected] Lilly (1659) , sig. B1r. For another passage in Lilly where he warns against the practice of predicting death, and other sixteenth-century English astrologers expressing caution on this matter, see Thomas (1973), p. 375. 2 The most famous case of antiquity is possibly that of the Roman astrologer Ascletarion, who predicted the Emperor Domitian’s death and paid for his daring prediction with his life (see Grafton, 1999, p. 124). Among Lilly’s contemporaries, Thomas Harriot had been imprisoned for casting the nativity of the king and the crown prince on the eve of the Gunpowder Plot (see Dooley, 2002, p. 154). 3 For a full account of these events and the trials of the people involved, see Carey (1987), pp. 41–56, esp. pp. 50–54; and Carey (1992), esp. pp. 138–153. 4 Carey (1992), p. 154. 1

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M. Azzolini / Studies in History and Philosophy of Biological and Biomedical Sciences 41 (2010) 135–145

astrological prophecies that included thinly veiled predictions of the execution of Charles I, completing his work after the dramatic event by penning a treatise entitled Secret observations on the life and death of Charles king of England in 1651.5 While in England astrology for a time moved outside the court and seems to have been practised mostly underground, this was not the case everywhere in Europe. We may even hazard the assertion that England constitutes an exception in the European panorama as regards its historical mistrust of astrology in the Late Middle Ages and the early Renaissance. As this essay will demonstrate, the practice of predicting the death of princes and popes was neither undocumented nor particularly rare in Renaissance Italy. Indeed, Italian political leaders were often actively involved in the production and circulation of astrological prognostications that addressed specifically this aspect of a person’s life. Such predictions, moreover, fulfilled specific functions within the information economy of Renaissance diplomacy: they could either inform a leader’s diplomatic praxis or, if made public, they could create a hightened sense of expectation about future events. While rather dubious, the practice of predicting someone’s death did not wane until at least the mid-sixteenth century, when a warning against it was issued by Sixtus V in a papal bull.6 The most strict and strongly worded ban, however, did not come until 1630, in the form of the famous bull of Urban VIII entitled Inscrutabilis, and even then we may wonder what its real impact on Italian astrologers’ practice was beyond their avoiding predicting the death of prominent figures publicly.7 Indeed, the forceful ban on judicial astrology was not so much motivated by theological arguments, nor by political fears alone (although these certainly existed), but more significantly by the pope’s deeply held belief in this predictive art, and his authentic apprehension for his own life.8 Urban VIII was so concerned about his life that, on at least one occasion, he had his astrological advisor Tommaso Campanella summoned to a special room in Castel Gandolfo to practice some elaborate ritual that would help him avoid the destiny inscribed in the stars.9 When he discovered that his own death had been predicted astrologically he acted swiftly and forcefully to ban the practice completely. But while the case—which involved the Vallombrosa abbot Orazio Morandi and a group of men from the Roman nobility and the curia—ended dramatically with Morandi’s incarceration and the issuing of the bull, such practices, I argue, had been in place for almost two centuries. Moreover, as I will illustrate, the reaction of those whose death was predicted astrologically was sometimes similar to that of Urban VIII, if not always in degree, at least in spirit: they often acted to restrict the circulation of this type of information. For all of the Renaissance princes involved, popes included, the problem was not so much judicial astrology—to which many of them resorted for their own political and personal ends—but the potentially subversive nature of ‘astrological intelligence’. In the


constantly shifting, and intensely unstable political scenario of late fifteenth and sixteenth-century Italy, where alliances were fickle, double-gaming common, and intense rivalry ripe, control over astrological information often became vital. While banning the circulation of astrological forecasts was frequently justified with the argument that these ‘rumours’ could generate social unrest among credulous and ignorant people, the real reason was that this information was often used and manipulated by political leaders attempting to undermine their adversaries.10 This seems to have been the case with Urban VIII, as the predictions regarding his death seem to have been actively encouraged by the Spanish, who were already preparing the ground for the next conclave.11 Renaissance leaders were well aware that astrology could be used as a powerful predictive (and, at times, propagandist) tool, but they also knew that in the hands of unscrupulous political enemies the very same art could be turned against them. Princes, popes, kings and court astrologers alike were thus confronted with a double-edged weapon that could backfire if not controlled appropriately. The astrologers’ response was to develop rhetorical and practical strategies to protect themselves against the occupational risks presented by their profession (often by stressing the conjectural, tentative nature of their art or by receiving protection from a powerful lord), while political leaders often chose to exert direct control over astrological information, either by keeping it secret, or by using it overtly for political gain, depending on circumstances.

2. Renaissance techniques for predicting death 2.1. Prorogations There were various ways in which an astrologer could set about predicting someone’s death. It was believed that a great deal of information about life, death and illness could be obtained from a person’s nativity. In casting a natal chart, there were three particular areas of the chart, known as houses, where information regarding the death of the client was thought to emerge: the sixth, the house of illness, where natural causes could be addressed; the eight, the house of death itself, where the nature and causes of death could emerge; and the twelfth, the house of hidden enemies, where deaths by violence could be discussed. There was, however, a specific technique that allowed a skilled astrologer to calculate the length of life of one’s client, and this was called prorogation. This technique had been described in Ptolemy’s Tetrabiblos, but was further refined by Arabic astrologers in the Middle Ages, and was covered extensively in Guido Bonatti’s widely popular astrological summa, his Tractatus astronomie.12 In all of these Arabic works the calculation of the length of life hinged upon two elements: the determination of the hyleg (or hylech), and that of the alcochoden

See Geneva (1995), esp. Chs. 6, 7 and 8. Lilly’s work is part of a larger book entitled Monarchy, or no monarchy in England. Thorndike (1923–1958), Vol. 6, pp. 145–149, 156–163; Ernst (1991), pp. 249–273. 7 Ugo Baldini discusses extensively the measures taken in Post-Tridentine Italy to ban astrology, and yet he admits that astrology remained a lively practice despite the fact that papal bulls were issued and books were banned (Baldini, 2001, p. 100 n. 75). 8 While certain authors brought forward theological arguments for the incompatibility of astrology and theology, they were mostly dogmatic and ignored the rich intellectual debate generated after the publication of Pico’s Disputationes adversus astrologiam divinatricem (1496). Germana Ernst suggests that in sixteenth-century Rome the debate shifted away from the truth or falsehood of divinatory arts to focus on their dangerous elements and the issue of political and social control (see Ernst, 1991, pp. 249–273 and esp. p. 262). Urban VIII was in the habit of having the horoscopes of his cardinals cast in order to predict their death (see Walker, 1958, p. 205). 9 The nature of these encounters and the accompanying ritual are recounted in Walker (1958), pp. 206–210. See also Ernst (1991), pp. 263–265, and Dooley (2002), pp. 155– 156. 10 The Spanish theologian Benito Pereyra, admitted as much in his treatise Against wrongful and superstitious practices in which he deplored the fact that not only common people but also princes and republics gave credit to astrological prognostications (see Ernst, 1991, p. 260). On the ‘power of words’ and the political uses of verbal communication among various strata of society, see now De Vivo (2007). 11 Walker (2000), p. 206. 12 Ptolemy (1940), III. 10, IV. 10. Among the Arabic sources one can include the popular commentary of Ptolemy’s Quadripartitum by Haly (Ali Ibn Ridwan, ca. 998–1067), and De nativitatibus by Omar (‘Umar Ibn al-Farrukhân al-Tabarî, eighth century A.D.). The same tradition is also summarized in Bonatti (1491), Bk. 9. The astrological terminology used in the Latin sources is explained in Broecke (2004), p. 227 n. 1. For the origin and circulation of these terms in the Middle Ages and the Renaissance, especially in the Arabic sources, see Kunitzsch (1977), pp. 35–37. 6

M. Azzolini / Studies in History and Philosophy of Biological and Biomedical Sciences 41 (2010) 135–145 Table 1 Number of years of life ascribed to each planet (table of the planetary years from Bouché-Leclerqu, 1899, p. 410). Planet




Saturn Jupiter Mars Sun Venus Mercury Moon

57 years 79 66 120 82 76 108

43 45 40 69 45 48 66

30 12 15 19 8 20 25

(or alchocoden), the two celestial bodies that were considered to be, respectively, the ‘giver of life’ and the ‘giver of the years’ in the nativity.13 The alcochoden was particularly important: each planet, depending on its favourable, neutral, or unfavourable location in the geniture could ‘give’ the client a certain number of years (see Table 1). Once it had been established which planet was the alcochoden, and consideration made of how well it was placed, the astrologer could then add or subtract further years or months to the initial number of years, depending on a number of other factors to be considered.14 In itself the technique was both lengthy and complicated, and there were discrepancies and disagreements both in the classical sources (e.g. Ptolemy and Dorotheus of Sidon), and in the Arabic tradition.15 In the context of this essay, therefore, it is not so important to grasp the technique itself, but rather its use and application. Indeed, the familiarity of Renaissance astrologers with prorogations is testified by four illustrious examples: that of the calculation of the length of life of, respectively, the Duke of Milan Galeazzo Maria Sforza (1444–1476), the Grand Duke of Tuscany Cosimo I de’ Medici (1519–1574), and popes Pius IV (1499–1565) and Gregory XIII (1502–1585).16 Not only do all these examples demonstrate the central place occupied by prorogations in Renaissance astrology, but also, and more importantly, they cast light on the practical and political nature of this type of information. The calculation of the length of life of Galeazzo Maria Sforza provides an interesting example of the different results that different astrologers arrived at for the same person. The Milanese astrologer Raffaele Vimercati, a contemporary of Galeazzo Maria and a citizen of his duchy, provided the calculation of the length of life of the duke in an elaborate iudicium (a detailed interpretation of


the future duke’s geniture) that was presented to Galeazzo’s father as a propitiatory gift soon after its completion in 1461.17 Not surprisingly, considering the context of patronage in which Vimercati operated, his forecast was wildly optimistic: our astrologer calculated that the future duke would live eighty-one years and eleven months. Vimercati certainly had a vested interest in producing a very positive result: over the following decade he would seek repeatedly to gain the patronage and support of the future duke, offering his services as an astrologer and, in return, obtaining courtly posts for his sons.18 Years after the death of Galeazzo Maria, who was assassinated on Boxing Day of 1476, another Milanese astrologer, Girolamo Cardano, could, with more confidence, show that the calculation of the length of life gave a neat thirty-two years, the exact age of the duke of Milan when he died.19 One way to explain these different results is to stress the different conditions in which the two astrologers operated: Vimercati when the duke was still alive and he could therefore directly influence the latter’s life and career, Cardano when the duke was dead and the Sforza dynasty had been ousted from Milan. And yet, while a certain level of opportunism may have played a part, such an explanation may be highly reductive.20 We should think, instead, of the different genres to which these predictions belonged: Vimercati’s iudicium was meant as a sort of personal vademecum, a book of advice written for the future duke to prepare him for his adult life, giving him counsel on his humoral complexion and character, warning him of future dangers and difficulties, alerting him to his proclivity for certain illnesses in a manner not so very different from another book of advice that was written for him by a court physician, the Ordine da servare nella vita del conte Galeazo (The order to follow in life by Count Galeazzo) of Cristoforo Soncino.21 Cardano’s prediction, instead, was part of a series of genitures that he collected to exemplify the soundness of his own art (a purpose that Galeazzo’s geniture fulfilled admirably). In short, the same technique produced not only very different results, but had also markedly different functions. Indeed, the fact that a similar astrological vademecum was drafted by the Tuscan astrologer Giuliano Ristori for Cosimo I de’ Medici shortly after Cosimo’s unexpected appointment as Duke of Florence in 1537 seems to suggest that this format was not unique to Vimercati and that it may have constituted a marginal, but important, astrological genre of its own.22 Much like Varesi, Ristori—who had previously predicted the violent death of

13 Omar (1533), p. 120: ‘Cum que sciveris hylech & alcochoden scito quod alcochoden significat annos vite nati, & eius pericula, hylech vero significat vitam nati, si dues voluerit’. In order to calculate the alcochoden, or giver of the years, one has to know first the hyleg. On the certifying of the years of the native and his life see Bonatti (1491), sig. S4v: ‘Postquam vero sic feceris et certificatur fueris de ylec et alcocoden poteris de annis nati ac de ipsius vita certificari: et de ipsius vita utrum scilicet sit futura longa vel brevis, salubris vel periculosa et de ipsius accidentibus bonis seu malis, ac de ipsius prosperitatibus, necnon et de adversitatibus suis poteris certificari. Ylec enim significat radicem vite, alcocoden vero numerum annorum eius, quoniam status vite accipitur ab ylec, datio vero annorum accipitur ab alcocoden. Sed tamen neuter illorum sufficit ad dandum vitam nato sine altero sicut enim vir solus non sufficit ad generandum sic nec mulier sola sufficit ad concipiendum seu gignendum. Unus enim sive alio gignere non potest: ylec enim dat vitam formaliter, alcocoden dat eam effective’. I have not been able to consult Robert Hand’s translation of Omar’s work in this instance. 14 For the determination of the length of life and the ‘planetary years’, see Bouché-Leclerqu (1899), pp. 404–428, as well as Tester (1987), pp. 84–87. 15 As indicated by Haly Avenrodoan (Ali Ibn Ridwan, ca 998-1067) in his commentary of Ptolemy’s Quadripartitum, there was little consensus as to the way to determine the hyleg and alcochoden. See Haly Avenrodoan (1493), fol. 65r–a: ‘Sapientes antiqui huius artis concordati sunt quod significatio vite debet accipi a dominio locorum principalium et eorum fortitudine in nativitate. Sunt tamen diversarum opinionum in manieribus quibus sciri potest quantitas vite quoniam eorum sunt qui reputant quod quodlibet luminarium quando fuerit in aliquo angulorum in quocumque sit aptum sit esse yleg. Et generaliter quando multe dignitates coniungentur alicui luminari preponunt illud, et accipiunt ab eo significationem quantitatis vite. Et sunt aliqui qui reputant . . . et sunt alii qui dicunt quod . . . et alii qui dicunt quod . . . ’; similarly, Omar (1533), p. 120: ‘licet quidam astronomi solo hylech utantur, & alchocoden non curant. Aliter locus dicitur vitae hylech, eo quod ab eo quaeratur status vitae, & alchocoden dator vel significator annorum dicitur, sed redeamus ad librum’. 16 Other examples can be cited: for instance, the Mantuan astrologer Bartolomeo Manfredi used both the technique of prorogation and that of the revolution of the year to predict the time of death of the Duke of Ferrara Borso d’Este for his lord Ludovico II Gonzaga. See documents in Signorini (2007), pp. 381–382. 17 BT, MS Triv. 1329. 18 ASMi, Fondo Autografi, Medici, 219, ins. 45, Raffaele Vimercati to Galeazzo Maria Sforza, 23 November 1474. 19 For a detailed analysis of these two examples, see Azzolini (2009), esp. pp. 6–15. 20 Unless we equate all court astrologers with opportunist tricksters other reasons need to be adduced to explain the nature and tenure of their predictions. All the astrologers discussed in this article were highly educated, university trained practitioners and it seems safe to assume that, with the due exceptions, most practitioners had a certain intellectual integrity. 21 This text could be defined as a Regimen sanitatis specifically drafted for the young Galeazzo. On this text, as well as other educational treatises for Francesco Sforza’s children, see Ferrari (2000). On the genre more broadly, see Nicoud (2007). On the related genre of the Taquinum sanitatis, see now Hoeniger (2006). 22 Cf. the contents of the two works as described in Azzolini (2009), p. 27 n. 16, and Castagnola (1989), p. 128. Cosimo’s horoscope, however, is both more extensive and sophisticated than that of Galeazzo.


M. Azzolini / Studies in History and Philosophy of Biological and Biomedical Sciences 41 (2010) 135–145

Alessandro de’ Medici, first Duke of Florence and Cosimo’s predecessor23—felt the need to provide the new duke not only with information on the astral influences that would pertain throughout his lifetime, but also on the possible dangers presented by his enemies and political adversaries.24 Predictably, given the philo-imperial role assumed by Florence after the marriage of Alessandro de’ Medici with Emperor Charles V’s natural daughter Margherita of Austria, Ristori indicated to Cosimo that his relationship with Pope Paul III and Francis I would not be easy, but that the stars favoured him in his relationship with Charles V, Francesco Maria della Rovere, Federico II Gonzaga, and Ercole II d’ Este.25 Raffaella Castagnola’s study provides a wealth of information about Ristori himself and his horoscope, together with a full transcription of the text.26 For our purposes, however, only a small part of this lengthy text is of relevance, namely its third chapter, which is fully dedicated to the calculation of the length of Cosimo’s life. Here Ristori indicates explicitly that there were two ways in which to calculate this, ‘the first [method], that of Ptolemy, and the other, socalled common’.27 According to the first method, Cosimo would not die before having reached his seventy-ninth year, as this is the number of equatorial degrees between the placement of the Moon in the chart (15°14 Sagittarius), and its square aspect on the left quadrant (15°14 Pisces).28 By the second method, that of the Arabs, however, one needed to look at the hylech and the alchocoden. After some deliberation, Ristori established Venus as the alchocoden, and, as Venus was in an angle (and thus nicely placed), this promised Cosimo almost the maximum number of years, which he determined to be, according to calculations explained in Haly Abenragel, seventy-eight years and three months.29 Ristori thus drew on the authority of two different methods, both in general agreement as to the length of life of his patron. He also ostensibly drew on the authority of his sources, both classical and Arabic, and tried to explain the process by which he obtained those numbers and not others, thus ascribing a sense of accuracy to his own calculations. By all accounts, therefore, Ristori’s vademecum does not read simply as a self-serving exercise in flattery and propaganda, but as a genuine, albeit idealistic, attempt to forecast all that Cosimo’s life had to offer by reading his horoscope. Particularly when read in light of Ristori’s allegedly accurate astrological prediction of Alessandro’s death, his astrological confirmation of Cosimo’s suitability for rule acquires

clear political significance. In short, Ristori’s vademecum should be read as an exercise aimed at providing political legitimacy and support for the new duke.30 Of course, court astrologers often had a vested interest in predicting long lives for their powerful clients, but this does not mean that the practice of prorogation was utterly meaningless or fraudulent. It was also the case that some who asked astrologers to calculate the duration of the lives of other people (and not themselves) did not enquire it for any other purpose than to know, within a certain degree of certainty, what would happen to these people in the future in order to help the questioners plan their own actions.31 The series of letters written by the Venetian astrologer and mathematician Annibale Raimondi to Guidobaldo II della Rovere, Duke of Urbino (1514–1574), provide a case in point. From the letters extant, it seems that the duke was in the habit of asking the astrologer how long a certain pope would live. A letter dated 4 October 1560, for instance, indicated that, according to Raimondi, the recently elected pope of the time, Pius IV, would live past his seventieth year, if, he added, ‘he looked after himself’.32 ‘The Moon’, Raimondi explained, ‘governs the ascendant, and it is placed in the house of illness; and if it were not in a propitious aspect with the Sun and Jupiter as it is, His Sanctity would already be dead’.33 The Sun and Jupiter promised him a long life, possibly beyond his eighties, Raimondi repeated, but ‘if His Sanctity wishes to shorten it, he could do as he pleases’.34 The pope lived only another five years, reaching the age of sixty-six, a little short of what Raimondi had predicted, but probably long enough to give credibility to his prediction. After all, the wise Raimondi had put the stress, all along, on the pope’s free will and his level of self-care. The fact that Guidobaldo wrote again a few years later posing the same question about another pope, Gregory XIII, clearly indicates his own trust in his astrologer’s skills.35 Raimondi did not reveal exactly how he had calculated Gregory XIII’s length of life, which he established to be seventy-three years and six months, but once again he added enough technical details to provide authority for his prognostication. Mars was ‘the giver of the years’, and the favourable placing of Jupiter in the house of religion, in Aries and in his triplicity, added more years to those already given by Mars. Yet, he specified, the pope had to be moderate: as Mars was angular in the medium coeli and looked

23 This is recounted in Varchi (2003), Vol. 3, pp. 262–263: ‘Né voglio lasciar di dire che gli fu predetto e pronosticato più volte, e per via di sogni, come da un paggio da Perugia, il quale era infermo, e per arte d’astrologia, come da maestro Giuliano del Carmine, il quale fece la sua natività (benché costui, secondo l’usanza di cotali astrologi, andava indovinando più quello ch’egli pensava che dovesse piacere al principe, che quello che fosse la verità) non solo ch’egli sarebbe ammazzato, ma scannato; e scannato, chi diceva il proprio nome, da Lorenzo de’ Medici, e chi lo descriveva . . . si conosceva espressamente che intendevano di lui’. On astrology and Alessandro’s death, see now Broecke (2000), pp. 175–186. 24 Castagnola (1989), p. 128. 25 Ibid., pp. 182–183. 26 Ibid. 27 Ibid., p. 140. It is clear from what follows that the common method is that of the Arabs. 28 This is explained in Ptolemy (1940), III.10. Here Ristori seems to apply the rather complex method of primary directions and basing his calculations on degrees of right ascension from one point to the other on the celestial sphere. 29 Ristori makes explicit reference to Haly Abenragel. I have consulted Haly Abenragel (1551), Pars IV, Cap. 5, p. 151: ‘De significatione alchocoden quando non habet bonitates completas’. 30 On the political relevance of his horoscope, see for instance Segni (1857), p. 337: ‘Dicevano ancora gli matematici ed astrologhi che Cosimo aveva una natività felicissima, ed il capricorno per ascendente in quel grado appunto nel quale l’ebbe Ottaviano imperatore, e come l’ha ancora oggi Carlo Quinto . . . ’. On the astrological elements present in Medicean artistic commissions, particularly in relation to Ristori’s horoscope for Cosimo, see Cox-Rearick (1984), pp. 173–174, 205–220, 261–269 and esp. pp. 269–283. 31 Of course ‘truth’ and ‘exactly’ are relative terms, especially when considered from a modern perspective, but we cannot explain the existence of examples of calculations of life that were not markedly flattering and utilitarian in any other way. 32 ASF, Ducato di Urbino, I, 217, Annibale Raimondi to Guidobaldo II della Rovere, Venice, 4 October 1560, fol. 465r–v: ‘Quanto aspetta al vivere di Sua Santità, questa sua natività dimostra che passerà gli anni 70 se si vorrà governare circa il vivere, et questo farà farlo [sic] per forza se vorà vivere lungamente in papato. Questo dico perché la Luna, patrona de l’Ascendente suo, si truova nella case de l’infermitadi, et se ella non fusse in aspetto gratioso col Sole et Giove come è fin hora, Sua Santità sarebbe morta’. I wish to thank Stefano Dall’Aglio for indicating these letters to me. 33 Ibid., fol. 465v. 34 Ibid.: ‘che secondo li corsi de’ cieli et stelle che harebbe et passerebbe gli anni 80, per ciò che Sole et Giove gli pomettono [sic] lunga vita, ma se Sua Santità se la vorà abreviare lo potrà fare a suo bel piacere’. 35 ASF, Ducato di Urbino I, 217, Annibale Raimondi to Guidobaldo II della Rovere, Venice, 12 December 1573, fol. 514r–v. In the same letter Raimondi says Pope Paul III (Alessandro Farnese) asked him through the intermediary of the bishop of Osimo to calculate how long ‘Sua Beatitudine’ would live. From this letter it seems clear he is asking about his own life. Paul III’s penchant for astrology is well known. See Thorndike (1923–1958), Vol. 5, pp. 252–274; Zambelli (1985), pp. 229–323; Quinlan-McGrath (1997), pp. 1045–1100.

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scornfully at the ascendant, and retrograde Saturn was in the same house, it could be assumed that the pope was inclined to excesses of anger that could compromise his honour. Even considering the unfavourable position of the two malefics Saturn and Mars, however, the two benefics Jupiter and Venus would mitigate those negative effects, especially as they would be flanked by the positive influence of the Sun, who was the lord of the ascendant in the fifth house, the house of amusements, together with Jupiter and Venus.36 Much as the other astrologers examined in this essay, Raimondi, customarily exerted a level of caution and left room for free will. If he chose to, the pontiff could, indeed, make his life shorter. It seems also plausible that Raimondi’s astrological jargon was somewhat intelligible to his client, at least at the level of providing a sense of authority and reliability for his prognostications. Raimondi’s associations with the della Rovere dynasty stretched back several years, to when he had served Guidobaldo’s father Francesco Maria, possibly as a military astrologer, during his campaign in Lombardy.37 They also remained active beyond Guidobaldo’s reign, as Raimondi dedicated a treatise on tides to Guidobaldo’s son Francesco Maria II della Rovere. The length of such a relationship, spanning almost three generations, is thus powerful testimony to the perceived value of astrological counsel within the economy of Renaissance society. For his part, Guidobaldo’s interest in papal affairs was of necessity assiduous. Not only was he the grand-nephew of Pope Julius II (Giuliano della Rovere), but, as over-lord of much of central Italy, the Papacy had often meddled in the della Rovere affairs. Guidobaldo had learned this only too well when, in his youth, he had lost both the title of Duke of Camerino and the Prefecture of Rome in favour of Pope Paul III’s grandson Ottaviano Farnese.38 Given his delicate and precarious relationship with the Papacy, therefore, it is not surprising that he decided to resort to valuable astrological advice to monitor the political situation in Rome.39 The existence of examples of this sort illustrates quite clearly that, despite some cautiousness as to the certainty of these predictions, it was believed that forecasts of this sort were mostly sound and could be used effectively as a means of gaining useful information about future events. Equally clear is the fact that people, much like now, were particularly interested in the health of political leaders, and that, therefore, a pope’s life was scrutinized as much on earth as in the skies. 2.2. Interrogations Another way of finding out the time of death of a person was to use the practice known as interrogation, whereby a chart was


erected for the time of asking a question. The practice had its most forceful critics among sixteenth-century astrologers (most notably the Milanese polymath astrologer Girolamo Cardano), and yet it had a discrete currency in the fifteenth century, at least in some prominent Northern Italian courts.40 Two documented instances exist in which the dukes of Milan resorted to interrogations to find out if one of their enemies was going to die: the first interrogation was addressed by Galeazzo Maria Sforza to the Dominican preacher and astrologer Annius of Viterbo and it concerned the outcome of the illness of the King of Naples, Ferrante of Aragon; the second was that of Galeazzo’s brother Ludovico Sforza, which he addressed to his favourite astrologer Ambrogio Varesi da Rosate, regarding the life of Pope Innocent VIII.41 The question regarding someone’s chances of survival from an illness was covered extensively in the Arabic literature translated into Latin that was circulating in the Renaissance, particularly in Zael’s De interrogationibus (‘Signum sextum sive sexta domus cum suis interrogationibus et primo si infirmus sanabitur vel morietur’), Messahallah’s Liber receptioni (‘De infirmo, utrum liberetur an moriatur’), and Bonatti’s Tractatus astronomie (respectively, ‘Capitulum primum utrum liberetur infirmus ab egritudine qua detinetur an non’ and ‘Capitulum secundum de infirmo utrum evadet’), which was heavily indebted to the Arabic tradition.42 These works provided step-by-step instructions to answer the question of whether a sick man would survive or die, allowing the astrologer to draw a series of inferences from the chart cast at the moment of the interrogation. In all of them the most important elements in the chart are the ascendant, the medium coeli and the position of the Moon, but the techniques and the instructions vary slightly as to the level of detail. Messahallah, for instance, added to his general explanation two further examples (or case-studies) complete with charts,43 certainly making the technique attractive and user-friendly for Renaissance astrologers, while Bonatti expanded considerably on the explanations offered by the other two. The popularity of these works is not only testified to by the considerable number of extant manuscripts and Renaissance editions,44 but also by Annius’ interrogation for the duke of Milan just mentioned. The question was posed to Annius by the podestà of Genoa at the request of the duke of Milan, after the news that both Ferrante and his son Alfonso had fallen seriously ill had reached the Sforza court in the autumn of 1475. While the two households had long-standing family ties, the relationship between Galeazzo and Ferrante had deteriorated substantially over the years, reaching a breaking point in the summer of 1475, when the two courts withdrew their respective resident ambassadors as a sign of protest.45 For this reason, Galeazzo had very limited information about

36 ASF, Ducato di Urbino I, 217, Annibale Raimondi to Guidobaldo II della Rovere, Venice, 12 December 1573, fol. 514r–v: ‘Gli è il vero che queste due infortune, cioè Saturno e Marte, sono situate nella sua natività in luogo possente di far del male se Sua Beatitudine non si regolarà; ma perché le due fortune, ciò [sic] Giove e Venere, sono anch’esse ben locate, si deve sperare che remidierano alla malignità de l’infortune. Et così credo, perché essendo il sole patron de l’ascendente nella quinta stanza del cielo, che è luogo de spassi et d’alegrie, insieme con Venere e con Giove, farano sì che le due infortune converrano temperare la sua malignità, et perciò potrebbe giugnere Sua Beatitudine sino alli anni 74 della sua età, et regolandosi passare assai più oltra e intorno li 80’. 37 See Dennistoun (1851), p. 20. The della Rovere possessed a palazzo in Venice and Guidobaldo maintained strong intellectual and artistic ties with the city. His portrait by Bronzino remains famous. See now Verstegen (2007). 38 The most comprehensive treatment of Guidobaldo’s life remains Dennistoun (1851), Vol. 3, pp. 81–117. 39 Similarly, in the previous century, Ludovico II Gonzaga resorted to astrological advice to assess the inclination of the newly elected Pope Paul II towards him, as well as the nature and identity of his successor at Paul II’s death. See documents in Signorini (2007), pp. 373 and 382. 40 On Cardano’s critique of interrogations see Grafton (1999), pp. 144–145. On medical interrogations particularly, see Grafton & Siraisi (2001), pp. 69–131. More work needs to be done to assess the popularity (or lack thereof) of astrological interrogations in the Italian Renaissance. As rather ephemeral objects linked to a specific need and moment in time these may be harder to document than other practices. 41 Another example is provided by Bartolomeo Manfredi’s prediction of Borso d’Este’s death. See n. 16 above. 42 See Zael (1493), fol. 129r–v; Messahallah (1549), sigs. Miiir–Niiv; Bonatti (1491), sigs. p6r–p8v (fols. 117r–119v in the numeration given to the copy preserved at the University of Edinburgh Library). Translations of the Arabic texts are now provided in Dykes (2008). 43 As these two charts were cast for latitudes of about 40–45° N, it is possible that these were later additions. See Dykes’s comment to his translation in Dykes (2008), p. 455 n. 48. 44 David Juste counted at least thirty-five manuscripts and four printed editions of Messahallah’s work in the period 1484–1549. See his bibliographical note to the digital edition in the Warburg Institute’s Bibliotheca astrologica Latina numerica, (accessed 20 October 2009). Three editions of Bonatti’s work were printed between 1491 and 1550, all very popular. 45 For the political context of the interrogation, and the Latin transcription of the interrogation itself, see Azzolini (2008), pp. 619–632.


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Ferrante’s health: while his own sister Ippolita, wife of Ferrante’s son Alfonso, was sending daily bulletins, Galeazzo could not count on independent information coming from a trusted person who resided outside the court.46 It was probably for this reason that he thought of resorting to an astrological interrogation. The interrogation asked the following question: ‘Whether King Ferdinand (i.e. Ferrante of Aragon) is dead or if he will die, or will be saved’. Annius’ response to the duke’s request was presented to him on a single sheet of paper, with the chart of the interrogation at the top, and the interpretation of the same below. A reading of Annius’ interpretation clearly indicates that our astrologer was drawing, either directly or indirectly, from the Arabic tradition. Following these authors, Annius established which planet was the lord of the ascendant (in this case, Mars), and analyzed it in the context of the chart.47 With Mars both lord of the first house (the ascendant) and of the eighth, soon to go retrograde, far away from the pars fortuna, and below the earth in the sixth house—whose lord was combust and in his detriment48—Annius’ first conclusion was that Ferrante would die.49 Then, as instructed by the Arabic literature, he looked at the position of the Moon, which was free from evil influences, was moving away from Mars and Saturn, and the Sun separated her from the latter. It was also conjunct with the pars fortuna, in trine with the benefic Jupiter and in reception with him. All this indicated recovery.50 Yet, Annius challenged this superficial analysis, arguing point by point against the thesis that the Moon and the planet Venus were in favorable aspects and indicated recovery.51 On the basis of this explanation, he concluded that the king would die soon, if not immediately. Annius’ prediction was incorrect. Not only did Ferrante recover, but he also lived for another nineteen years. Yet the fear of his demise was enough to encourage Galeazzo to move his army to the Romagna, preparing himself for a possible intervention in support of her sister Ippolita and her husband.52 This example, thus, clearly shows how concrete political and diplomatic decisions were made on the basis of the sort of ‘astrological intelligence’ analyzed here. A further example in support of the thesis that real political decisions were made on the basis of astrological prognostications is provided by the second interrogation mentioned previously, that of Ludovico Sforza concerning the life of Pope Innocent VIII. In this instance, too, the querent knew that the person was sick, and wanted to know the outcome of the illness.53 Once again the reason was genuinely political: Ludovico had had a troubled relationship with Innocent VIII, who had taken sides with the Aragonese of Naples in the issue of Ludovico’s illegitimate governance of Milan in stead of his own nephew Gian Galeazzo Maria. The Aragonese had


gained Innocent’s support for a possible intervention in the Milanese affairs, and were even prepared to call for foreign intervention, if necessary.54 It was for this reason that Ludovico, anxious to have a new pope elected, asked his favourite astrologer Ambrogio Varesi da Rosate for help. The outcome of the interrogation was a rather dense, almost incomprehensible letter where Varesi explained step-by-step why the pope was going to die, and when. As he did not have the pope’s nativity—Varesi explained—he had to resort solely to the interrogation. Mars, he added, was the ‘significator’ of the chart together with Jupiter. More precisely, Mars was in his own house, Jupiter was ‘under the Sun’s rays’ and the Moon under the earth, in aspect with the Sun, who was the lord of the house of illness; Jupiter, furthermore, was lord of the ascendant and combust.55 In twenty-five days from the time of writing, moreover, Jupiter would be conjunct with Mars, lord of the house of death. This, he said, clearly indicated that the pope would die. Other elements in the chart confirmed such an inference, and this was further corroborated by a study of the ‘significator of the Pastor of the Faith’ in the revolution of the year (a technique of which more will be said soon).56 In this way Varesi was able to establish that the pope would die around the 10 of August, if not before. Indeed, Innocent VIII died on 25 July, a few days earlier than predicted. By then, Ludovico had already sounded his astrologer for additional information; more precisely, he wanted to know in advance if the future pope to be elected was a person favoured by the Sforzas. Varesi confirmed that this would be the case.57 Like prorogations, astrological interrogations of this sort were mostly of private nature: they were produced by astrologers who maintained confidentiality and provided a service in hope of obtaining something in return. While these practitioners may have wanted to please their clients, they still largely operated with intellectual rigour, accompanying their predictions with elaborate technical explanations drawn from a venerable astrological tradition. More significantly, these examples attest that, even if private, such interrogations had a powerful public and political dimension. Their circulation, therefore, needed often to be controlled or restricted. 2.3. Revolutions and annual prognostications The most public form of predicting someone’s death, however, was neither the individual horoscope nor the interrogation, but the annual prognostication.58 The genre itself was an Italian invention. The first traces of its existence are to be found in the Statutes of the University of Bologna of 1405, which specify that professors of astronomy and astrology had the duty of compiling a ‘Judicium ac

Ibid. Cf. Messahallah (1549), sig. Miiir–v: ‘Aspice scilicet cui iungitur dominus ascendentis, quod si dominus ascendentis iungitur planetae fortunae, & ipsa fortuna fuerit dispositrix dispositionis, ad quam accessit, nec reddit eam ad alterum, & nisi fuerit ipsa fortuna domina domus mortis, dic, quod non morietur illo anno, iussu Dei. Et si dominus ascendentis fuerit coniunctus malo planetae, vel domino domus mortis, qualiscunque fuerit dominus domus mortis, sive malus sive bonus, et ipse dominus ascendentis non fuerit receptus, nec recipit eum planeta ipse malus, vel dominus domus mortis, sive malus fuerit fortuna, aspice tunc Lunam’; and Bonatti (1491), sig. p7r (fol. 118r): ‘Si aliquis infirmus a te quesierit utrum liberetur ab infirmitate an non aspice ascendens et dominus eius, et lunam, qui sunt significatores interrogantis, et vide si dominus ascendentis fuerit in angulo ascendentis vel in angulo medii celi, significat eius liberationem’ (my emphasis). 48 According to Bonatti the Moon below the earth brings about death. See Bonatti (1491), sig. p7v: ‘Si autem dominus ascendentis vel luna fuerit sub terra, videlicet in secunda, vel tercia, vel quarta, vel quinta, vel sexta, nec fuerit iunctus aliquis eorum planete existenti supra terram significat eius mortem’. The lord of the sixth house was Mercury, conjunct with the Sun (combust) and in Sagittarius (its detriment). 49 ‘Non evadet ex hec egritudine. Probatur quia idem est dominus octavi et primi, propinquus retrogradationi, remotus a fortunis, sub terra in 6a, cuius dominus hodie combustus est in suo detrimento’ (see Azzolini, 2008, p. 587). 50 ‘Luna libera a malis in angulo significat evasionem, sed nunc Luna nullum malum aspicit quia cadit a Marte, a Saturno quoque separata fuit, imo Sol adscendet inter eam et Saturnum, ergo liberabitur . . . Luna juncta fortune evasionem dicit. At luna videtur a trino respicere Jovem et recipi ab eo, igitur evadet’ (ibid.). 51 Ibid. 52 Ibid., pp. 625–626. 53 The letter is fully transcribed in Azzolini (2005), pp. 183–184 n. 1. 54 Pellegrini (2002), Vol. 1, pp. 276–284. 55 Azzolini (2005), pp. 183–184 n. 1. On the meaning of these astrological terms see Eade (1984). 56 The significator of the pastor of the Christian faith was generally considered to be Mercury. 57 Azzolini (2005), pp. 183–184. 58 The importance of different media in the transmission of information is stressed in De Vivo (2007), esp. pp. 1–17. 47

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Taquinum’ every year, and that this was to be pinned to the university walls for students to read.59 While each professor had his own personal style of compiling these prognostications, it seems that a certain standardization of form and content was soon established and by the fifteenth century most prognostica contained a letter of dedication (often accompanied by an apology of astrology), a series of paragraphs containing astronomical information for the given year (sometimes followed by weather forecasts), a series of general chapters on standard topics such as war, disease and crops, some general predictions about people of various professions and walks of life (which were believed to be ruled by different planets), and, more importantly, single chapters on all of the major leaders of the time, including the Turks, and, of course, the pope (who often came first in the list). The prognosticon was often accompanied by the taquinum, namely a list of solar and lunar eclipses, as well as a list of favourable and unfavourable days in the year that originally were intended for medical use.60 The evidence suggests that the practice of casting iudicia was soon instituted in all major universities, and we have testimony of similar prognostications originating from Pavia, Ferrara, Rome, Venice, and Padua, among other places.61 Even a coarse reading of fifteenth and early sixteenth-century prognostications reveals a high number of occurrences of astrologers publicly predicting the deaths or serious illnesses of princes, kings and popes. Often enough, as I shall illustrate, these predictions were issued for reasons that went beyond the mere observation of the skies. Yet, historians of science and political historians alike have largely overlooked the purpose and function of this type of astrological prediction in the information economy of Renaissance Italy. Technically, the general parts of these prognostications were based on the revolution of the year of the world, and on the revolution of a leader’s nativity for those parts that related to single individuals. The revolution of the year is an astrological technique based on the erection of a celestial figure for the return of the Sun to a certain point in the sky: the first degree of Aries is used in the case of the revolution of the year of the world, and the date and time of birth in the case of a single individual. In other words, in order to find out what the year ahead promised, a Renaissance astrologer would cast the horoscope for the entry of the Sun into the first degree of Aries (solis introitum) and then interpret it accordingly. This technique was explained in some detail in many Arabic texts: these included Albumasar’s Flores astrologiae (a handy summary of the main aspects of this technique, giving various


rules for the interpretation of the horoscope),62 Haly Abenragel’s De iudiciis astrorum,63 Messahallah’s Epistola Messahalae de rebus eclipsium, et de coniunctionibus annorum mundi and his widely popular De revolutione annorum mundi,64 and, of course, Guido Bonatti’s widely read summa. An example may suffice to illustrate how these prognostications worked: in the 1494 prognosticon elaborated by the famous Ferrarese astrologer Pietro Buono Avogario and dedicated to Ercole d’Este, Duke of Ferrara, Modena and Reggio Emilia (1431–1505), our astrologer calculated, for the longitude of Ferrara, that the entry of the Sun into the first degree of Aries—the astronomical time when the Sun is on the vernal equinoctial point—would occur on 10 March at 19h50m (which is, in clock time, around 7.50 a.m. on the following day), with Mercury (actually, Venus!) ascending at 19° Taurus.65 He then noted that the ascendant of the year was in Taurus, a fixed sign, and therefore he concluded that the prediction for the revolution of the year would relate to all quarters of the chart (namely the whole year).66 He then added that there was to be an opposition of the heavy planets Saturn and Jupiter on 23 February in 7° Virgo (and Pisces) and established that the Moon and Venus would dominate the year, as Venus was in her own sign and the Moon was in the sign of her exaltation, in the ascendant of the year and in the first house at the time of entry of the Sun in Aries.67 Furthermore, there would be a solar eclipse on 6 March, at 20h57m (namely around 3.30 p.m. on the following day) and the luminaries would be in 27° Pisces, near the cauda draconis and in the eighth house, the house of death and terror. In the same month, on 21 March at 8h30m (around 4.30 a.m. on the following day) the entire body of the Moon would be eclipsed in 11° Libra, and in the house of death. An eclipse of the Moon would occur on 14 September, at 13h57m (around 9.13 a.m. on the following day), and on 6 January in the same year there would be a conjunction of Saturn, Mars and Venus.68 It is clear that these prognostications placed great importance in conjunctions and oppositions, as well as the placing of the planets that dominate the chart in relation to the various houses. The rest of the prognosticon interpreted such astronomical data in relation to various ‘classic themes’ such as the weather, war and peace, to move on, then, to address the revolution of the year of each political leader. As it pertains to war and peace, for instance, we are told that the fact that Mars in Aries was in the house of religion indicated that Italy would be invaded that year. Of course, such an explanation was likely to be obtained as much (or more) from knowledge of the events that were unfolding in Italy at the

59 See Malagola (1888), Rubrica LX: ‘Quod doctor electus ad salarium in astrologia det iudicia gratis, et etiam teneatur disputare’, p. 264: ‘Item statuerunt, ordinaverunt et firmaverunt quod doctor electus vel eligendus per dictam Universitatem ad salarium ad legendum in astrologia teneatur iudicia dare gratis scholaribus dicte Universitatis infra unum mensem postquam fuerint postulata, et etiam singulariter iudicium anni in scriptis ponere ad stationem generalium Bidellorum’; and Sorbelli (1938), pp. 109–114, esp. pp. 109–110. 60 This description is necessarily a summary; the genre developed and changed from author to author and from year to year, but the most consistent part, together with the astronomical data, remained the prediction of the fates of political leaders. The various examples of annual prognostica cited in this article are all included in a collection now held in BUB (shelfmark: A.V.KK. VIII.29). The prognostica are not paginated. I have given separate pagination (sig.) to each prognosticon. 61 For a manuscript prognostication of this sort by the Pavian professor Gabriele Pirovano, see BL, MS Arundel 88, fol. 28r–v. For prognostica published in Ferrara, Rome, and Padua see the numerous records in the British Library ISTC catalogue under ‘prognosticon’. Prognostica by Pietro Buono Avogario, for instance, were published in Ferrara, Bologna, Venice, Milan, and Perugia, those of Giovanni Basilio Augusonio in Rome, Milan, Modena, Venice and Geneva. 62 Albumasar (1488 or 1505). 63 Haly Abenragel (1551), pp. 352–410. 64 Both works are included in Messahalla (1549). De revolutionibus annorum mundi is also in Opera astrologica (1493). 65 Avogario (1494), dedicated to Ercole da Ferrara, sig. A1r: ‘Primum premito solis introitum in primum punctum vernalis equinoctii fore die 10 martii post meridiem diebus equatis hora 19 m. 50, hora Mercurii ascendente supra circulum emispherii, 19 Thauri ad meridianum inclite civitatis Ferrarie anno salutis 1494’. The printer must have confused Venus with Mercury ($ and Ú). On Pietro Buono Avogario, see Vasoli (1962), pp. 709–710. 66 Cf. Avogario (1494), A1r: ‘Secundo loco premitto: quia ascendens anni presentis est signum solidum ac firmum, mundi revolutio vincet omnes quartas’. Cf. Messahallah (1549), sig. Biiv: ‘Cum vero fuerit signum fixum ascendens, erit revolutio anni vincens omnes quartas anni et eo fortius erit si fuerit dominus in signo fixo’. 67 Ibid.: ‘His premissis dico Lunam & Venerem totius anni dominium possidere, quia in propria domo coeli hora introitus magni luminaris in primum punctum Arietis in ascendente anni & in prima domo discurebant [sic]’. Both the Moon and Venus are in the first house, but only Venus is in her mansion and in the sign of the ascendant (Taurus). The fact that the Moon is in angulo ascendentis, however, reinforces her power. Cf. Messahallah (1549), sig. Biiir–v: ‘Scito quod fortior planetis est ille qui fuerit in ascendente non remotus ab angnlo [sic], neque cadens, vel fuerit in medio coeli . . . Scito quod luminaria cum fuerint in aliquo angulorum erunt domini anni, nisi ipsum quod fuerit in angulo signum impeditum fuerit, quod si ita fuerit significabit impedimentum et debilitatem eiusdem climatis, quod signo illi subiicitur’. 68 When the data is compared with Regiomontanus’s astronomical data for the same year in his Ephemerides (1474) we notice some slight discrepancies regarding eclipses. It is possible that Avogario did not use Regiomontanus’s ephimeredes and calculated the values from the Alphonsine tables directly. I wish to thank Professor Richard Kremer very much for helping me check these values against Regiomontanus.


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time as from the astronomical data and the Arabic astrological texts available to Avogario (without this necessarily implying bad faith on his part, as his interpretation was understandably influenced by the historical context). It seems no coincidence that the house of religion was singled out for consideration: the French descent into Italy of 1494 had been presented as part of a prophetic design, and had as its declared goal the invasion of the Kingdom of Naples in order to launch an attack against the infidels.69 Equally unsurprising is the forecast for Ferrante of Aragon, who had to face the French army. Avogario’s entry for the most serene King Ferrante forecasts that, according to the indication of the heavenly bodies: He will feel sad, and will shed distrustful blood and perpetrate killings; he will be tormented by suspicions and great anguish about all that pertains to his kingdom. Beware, your Excellence, as you will have both hidden and declared enemies. Beware also from illness that could come from apprehension. Beware, I say, of pursuing any gain.70 While indicating what seemed rather obvious given the circumstances, Avogario could not successfully predict the untimely death of Ferrante from natural causes on 25 January 1494, a few days after Avogario had compiled his prognosticon.71 Read posthumously, however, such a vague prediction could have easily been interpreted to be a warning addressed to the king himself about his own health. Quite understandably, when it came to publicly predicting the fate of major political leaders astrologers were either cautious, or, on the other hand, clearly partial. As these prognostications were dedicated to their lords or prospective lords, it is not surprising to find that in most cases they provided as positive predictions as possible for their dedicatees. Once again, this reflected the function of astrological public prognostications within the information economy of Renaissance Italy; they were meant to create expectations and influence public perception. One such example is offered by the prognosticon for the year 1486 written by Eustachio Candido of Bologna and dedicated to Matthias Corvinus, King of Hungary and Bohemia (1443–1490), which addresses the ‘most serene King of Hungary’ with the following words: O, my King, live for eternity! You, King of Kings, will win wars and be lucky, you will gain a large kingdom at the death of the Holy Roman Emperor, because of the conjunction of Jupiter, Saturn and Mars in the first degree of Capricorn. There will be doubts about you having a son, and you will suffer some sort of impediment, because of the square aspect of Mars and the conjunction of the Sun with Saturn. Beware, O Most Serene Majesty, of poison, because of a wife, now noble but who was not so before, or because someone in jail, who, if he escaped, would inflict damage on Your Most Serene Majesty, because of the trine aspect of the Sun with Mars, and the square aspect of

Saturn and Venus around the 13th of July and up to the first of August.72 Among political elites it was no secret that Matthias Corvinus had imperial aspirations; equally well known was his keen interest in astrology, and his patronage of astrologers.73 It seems quite certain that Eustachio Candido was trying to flatter Matthias, possibly in order to receive some benefits from him, but what is even more evident is that such a favourable prediction could be actively used to justify and facilitate Matthias’ own aspirations. At least in this case, however, our astrologer neither reaped the benefits of his work, nor was he right in his prediction: that year saw neither the death of Frederick III, nor the coronation of Matthias. Indeed, Matthias died suddenly in 1490, thus leaving his aspirations to the imperial title unfulfilled, while Frederick III lived on for another three years. Other predictions, however, may have had a more tangible impact. A good case in point is the prediction of the death of the aforementioned duke of Milan, Galeazzo Maria Sforza. Despite the very promising prediction of the Milanese astrologer Raffaele Vimercati mentioned above, Galeazzo’s life was cut short by a group of conspirators on 26 December 1476. This was a classic case of a death foretold: in 1474 a number of astrological prognostications appeared in Bologna and Ferrara announcing the death of an Italian prince. The inferences in the annual prognostications of the astrologers Girolamo Manfredi and Marsilio da Bologna were vague and undetermined, and yet this was enough to incense Galeazzo Maria, who interpreted them as being directed towards his person. His response to these rumours was two-fold: on the one hand he used diplomatic means to put pressure on the duke of Ferrara and the lord of Bologna to forbid their astrologers from making such predictions, on the other he sent death threats directly to the astrologers, thus making sure that the message would get across.74 When he expressed his concerns about these forecasts to his resident ambassador in Ferrara, it was clear that he was fearful of public unrest in his domain: You know how serious things become when some evil opinion spreads among the populace about some looming calamity, as it is often done by daring and vain astrologers who, in divining freely about occult things which are known only to God, unwisely predict the death of princes, wars and famine, and they even come to identify unambiguously the person who should meet such a terrible fate. Serious and honest people pay little attention to this type of prognostications; the populace, however, listens to them and waits in suspense, often giving rise to ideas that create chaos in those states and principalities.75 Galeazzo’s grievances flowed into a heart-felt appeal to his ambassador that those practitioners ‘who have the presumption, in their prognostications, to name or specify a prince or a lord, either by making explicit or implicit mention of him’ be excommunicated by the pope.76 He added also that ‘while these prognostications go

69 Avogario (1494), sig. A2r: ‘Et tamen significatio fatorum magna de multitudine inimicorum Italiam invadentium propter Martem in Ariete constitutum in domo religionis existentem qui omnino bella in Italiam designat’. 70 Ibid., sig. A2v: ‘Illistrissima ac excellentissima regis Ferdinandi maiestas sumpta indicatione ab astris merorem sentiet hoc anno: & damna & sanguinem fundet suspectum, & magna angustia cruciabitur propter ea que ad imperium pertinent. Caveat Excellentia sua quia multos inimicos occultos habebit atque patentes. Caveat etiam ab egritudine quam consequetur propter metum. Caveat dico ut omne emolumentum consequatur & optatum’. 71 Ibid., sig. A5v: ‘Actum Ferrarie anno legis gratie 1494 die primo Ianuarii per eximium artium & medicine doctorem D. Magister Petrum Bonum Advogarium Ferrariensem’. 72 Ibid., sig. A2r: ‘Rex mi in eternum vive. Tu rex regum in bello victor eris & fortunatus, dominum magnum habebis propter mortem imperatoris ob coniunctionem Iovis, Saturni & Martis in prima Capricornii. Dubium est de filio ne aliquod impedimentum patiatur propter quadraturam Martis & coniunctionem Solis & Saturnii. Caveat serenissima maiestas tua a veneno propter mulierem nunc nobilem que non erat nobilis propter incarceratum quod si evaserit tua serenissima maiestas danum consequetur ob triplicitatem Solis & Martis & quadraturam Saturnii & Veneris circa tertiumdecimum Iulii & primum Augusti’. 73 On Corvinus and his imperial aspirations, see Nehring (1975), Gutkas (1982), and Hoensch (1998). On his patronage of astrologers see now the excellent study of Heyton (2007). 74 For a detailed account of these events see Azzolini (2009), esp. pp. 15–21. On Manfredi, see now Duranti (2008). 75 Galeazzo Maria to Sacramoro da Rimini, Pavia, 14 July 1474, as quoted in Gabotto (1889), p. 404; my translation. 76 Ibid.

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against the will of God, they are also done in bad faith, to please the will of their lords by flattering and wheedling them’.77 But he did more: aware of the power of words, he also threatened Ercole d’Este of paying him in kind—by asking his astrologers to issue an unfavourable prediction about the Este duke—if he did not intervene to stop his own astrologer from giving negative forecasts about the Sforza.78 This is a clear indication that Galeazzo was aware of the potential propagandistic and overtly political nature of these predictions. These prognostications obviously reflected the hatred of some people towards the duke of Milan, and indeed their reference to Galeazzo’s ‘hideous brothers’ and his ‘hidden enemies’ must have struck a chord.79 Two years later Galeazzo’s brothers Ludovico and Sforza Maria attempted (but failed) to overthrow him, but on December of the same year three young Milanese noblemen ambushed him in the church of Santo Stefano and the attack left him dead on the church floor.80 It was not the gullible populace, therefore, that constituted a direct threat, but, instead, it was Galeazzo’s political rivals, who used such predictions as a pretext on which to act. It is thus clear that not all these predictions were innocently made, and that politics and astrology often interwove in potentially dangerous ways. Equally political were the predictions of another fifteenth-century Ferrarese astrologer, Antonio Arquato, who often dedicated them to Ferrante of Aragon’s son, Alfonso.81 His yearly prognostication for 1491, for instance, did not contain a particularly favourable forecast for Lorenzo the Magnificent. Based on the revolution of Lorenzo’s natal chart (which gives his birthday as 31 March), Arquato concluded that Lorenzo would be highly regarded and happy in the first part of the year, but that then he would be plagued by a very serious illness that would nearly kill him, as would dissent and discord also among other princes.82 Much more negative, and significantly more obscure, however, was his prediction for the revolution of Pope Innocent VIII’s nativity on 18 April, about which Arquato premised that it was possible that the pope would not even reach that day alive! This was followed by a rather intricate series of unfavourable planetary positions and aspects (some apparently referring to the previous year) that promised illness, because—Arquato went on to explain—Mercury, lord of the ascendant in the radix (the pope’s geniture), was retrograde and in the house of death in the revolution; Mars, the alchocoden and lord of the year with the Moon, was in the same house; and the Sun was ‘infected’ by the malefic Saturn.83 All of this, Arquato concluded, would bring about a series of horrendous diseases until his death, unless, he added, the pope followed his advice and took precautions to avoid it.84 Neither Lorenzo nor Innocent died that year, but the prediction, at least for their contemporaries, had a clear political undertone. 77


Arquato’s dedicatee, Alfonso of Aragon, was the future heir to a Kingdom whose fate was being decided around those years, and the relationship between Naples and the Papacy had been particularly strained since the late 1480s, when Alfonso’s father Ferrante had risked excommunication for attempting to exert his dominion over the Papal lands of Southern Italy without paying Innocent for his privilege.85 For a time the pope had threatened Ferrante with foreign intervention and it is not surprising to find Arquato’s interpretation aligned with his dedicatee’s hope that Innocent would die as soon as possible. Lorenzo de’ Medici, however, was a collateral casualty, as he had never been openly against the Aragonese, even if not openly in their favour either. In any case, the two men did not die that year, as Arquato predicted (they both, however, died the following year). Despite the fact that the following year Ferrante reached an agreement with the pope, in 1492 Arquato—possibly unaware of the recent negotiations—renewed his efforts to campaign against the pontiff. His prediction for that year mirrored in spirit that of the year before. His forecast for Ferrante of Aragon, not surprisingly, was once again glowing, but his prediction for Innocent VIII was even more caustic than the previous year: Although he has lived up to now more by the gods’ will than by the wish of the stars, if I am not an unskilled practitioner of celestial meaning, this year, which will start on 18 April, Innocent VIII, pontifex maximus of the Christian religion will die because the algebutar and the lord of the years are in the house of death, and the lord of the horoscope combust in the house of illness, unless he has provided an incorrect date of birth. Death, then, by the movement of the stars, will deprive that unpolished, weak man of the Roman seat that earlier came from those below you, those who are like you, and those above you.86 According to Arquato, this time Innocent VIII was definitely going to die, and indeed the prediction proved right, as Innocent VIII died on 25 July after a short illness. We may think that these and other prognostications were not noteworthy, but Galeazzo Maria Sforza’s concrete political concerns outlined before suggest the opposite, and so do the other examples cited in this essay. It is clear that political leaders who either requested or banned the circulation of these prognostications were fully aware of their political and social dimensions. The political and historical interest of this type of information is also clearly attested by the fact that some of these predictions found their way into contemporary chronicles or histories, as in the case of the chronicle of the Sienese humanist-historian Sigismondo Tizio, who dutifully copied down Arquato’s passage of Innocent’s death, word for word, in his Historiae Senenses.87 If we

Ibid. Azzolini (2009), p. 18. 79 Ibid., p. 19. 80 Ibid., pp. 17–21. 81 On Arquato, see Garin (1962), pp. 299–301. 82 Arquato (1490), sig. A6v: ‘El Magnifico Lorenzio de Piero de Medici comenzarà a Zenaro, dove serà honorado et felice nel stato in una parte de lo anno, ma oltra una infirmitate grave nela quale titubarà ale morte, temerà la morte per gran disidie et inimicitie de principi’. 83 In order to verify Arquato’s astronomical/astrological data we would need to know the time when Arquato thought the pope was born. I have yet to locate a geniture for Innocent VIII, but the chart for the election and the enthronement of his successor are in BOD, MS Canon. Misc. 24, fol. 9r. 84 Arquato (1490), sig. A7v: ‘Inocentio papa octavo . . . la cui revolutione serà a dì 18 de aprile se infino a quello di serà vivo, che impossibile quasi pare che sia, perché la tarda infortuna alcelchedeni [alchochoden?] delo anno superiore in casa dela morte et la Luna dominatrice delo horoscopo conzunta cum Marte in opposito dela divisione de una mortifera infirmitade el minaciava . . . et perché Mercurio signore delo ascendente dela radice et dela decima et prima anche dela revolutione in casa dela morte retrogrado è trovado, et Marte alcochoden e signore delo anno cum la Luna in la tenebrosa casa è trovado el Sole fiando infecto da Saturno, da poi questa pompa comencirà a tristarse dala fortuna adversa dove delo animo et salute sua serà molestissimo; da varii cinortiferi morbi serà conquasato infino alo termene ultimo dela morte dove usi diligente cura e consiglio a ciò che la propinqua morte sua possa evitare’. 85 See Pellegrini (2002), pp. 169–186, 252–265, and 276–277 on the peace signed between Naples and the papacy. 86 Arquato (1491), sig. A6r: ‘Innocentius octavus christiane religionis pontifex maximus quamquam numinum potius nutu quam siderum votibus hactenus seculum vivat, anno instanti, cuius principum 18 aprilis erit ni sumus opifex etereos sensus inpotens, conficiat, ex algebutar et domino anni in mortis domicilio, nec vero domino horoscopi cremato in langorum domo ni mendosum eius natale obtulisset. Mors hunc e romano solio deturbabit illum incultum informidatum quod ante ex subditis, emulis ac proceribus agitando astrorum nutu’. 87 See BNF, MS II. V. 140, Vol. VI, p. 273. This is an eighteenth-century copy of the autograph now at the Vatican Library (MSS Chig. G.I. 31–35, and G.II. 36–40). On Tizio’s Historiae, see Piccolomini (1903). On the importance of this work for the history of prognostications and broadsides, see Zambelli (1986), especially n. 33. 78


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consider also Ludovico Sforza’s astrological interrogation about Innocent VIII’s fate, it seems clear that predicting the pope’s death was not such a rare occurrence, but, rather, relatively common practice. It is also abundantly clear that this type of prognostication had great currency in the information economy of Renaissance diplomacy. 3. Conclusions This essay has illustrated a series of astrological prognostications (and the different media in which they were transmitted) that, while at times pursued in secret, had often a direct public impact. The manipulation of ‘astrological intelligence’ for political purposes was not the only weapon in the arsenal of Italian political leaders, but it was certainly a powerful means with which to foster one’s interests at the expense of those of one’s enemy, one which political historians have largely ignored. As such, not only do these documents constitute an important source for the history of astronomy and astrology, but also for political and social history. As noted, the effect that these prognostications could have on a leader’s enemies and his own populace was often the cause of great concern. This is confirmed by the justifications provided by Pope Urban VIII at issuing the ban: the penalties inflicted were specifically intended to discourage ‘the prediction of future occasions of wars, revolutions of states and princes, and the deaths of the latter [e.g. Urban himself]’ that could create unrest.88 It was clear that these weapons could be used by Renaissance princes to undermine their political rivals. Of course, there were people who found great satisfaction in pointing out how ridiculous such predictions were, most memorably, possibly, Pico della Mirandola, who scathingly pointed out how the Bolognese astrologer Girolamo Manfredi himself failed to predict his own death.89 Even if skeptics were abundant, however, there was general concern about the lack of control over this type of information; once in circulation, astrological prognostications could potentially lead to social and political unrest. This is the reason why most lords and princes did not always take such wild predictions lightly, and why Urban VIII felt necessary to ban the practice of predicting death astrologically. Acknowledgements I would like to thank the Carnegie Trust for the Universities of Scotland for kindly supporting some of the research on which this article is based. References Archival sources and manuscripts Bologna, Biblioteca Universitaria (BUB). Incunable A.V.KK. VIII.29. Florence, Archivio di Stato di Firenze (ASF). Ducato di Urbino, I, 217. Florence, Biblioteca Nazionale (BNF). Ms II. V. 140 (formerly Magl. XXV, 671–683). London, British Library (BL). MS Arundel 88. Milan, Archivio di Stato di Milano (ASMi). Fondo Autografi, Medici, 219, cart. 45. Milan, Biblioteca Trivulziana (BT). MS Triv. 1329, Liber iudiciorum in nativitate Comitis GeleazMarie Vicecomitis Lugurum futuri ducis. Oxford, Bodleian Library (BOD). MS Canon. Misc. 24.

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