HOROSCOPES
The casting of horoscopes, diagrams containing information about the position of celestial bodies at a specific time and place that were consulted and reinterpreted over centuries, has a long history that goes back to antiquity: its origins can be firmly placed in ancient Babylonia, from where astrological practice spread to Egypt, Greece, and the Roman and Abbasid Empires, stretching as far east as India. After being condemned by the Christian emperors as a pagan divinatory practice in the fourth century CE, and having temporarily been eclipsed from sight within the confines of the Roman Empire by the sixth century, astrology and the casting of horoscopes flourished again in medieval and *Renaissance Europe starting in the twelfth century, arguably reaching its peak in popularity in the late fifteenth and sixteenth centuries. Twelfth-century Iberia represents the cradle of this revival, as a significant number of Arabic and Judaic astrological texts were first translated into Latin here and later disseminated across Europe through manuscript and print. By the fourteenth century, astrology was firmly embedded in the university curriculum of many European universities, and the casting of annual astrological predictions and natal horoscopes was one of the routine tasks assigned to Italian university professors teaching the science of the stars.
The Hellenistic origin of casting horoscopes is clearly revealed by the modern-day term, which derives from the Greek hōroskopos, from hōra, “hour,” and skopos, “observer.” As the composite word suggests, the term refers to the observation of a specific time, more precisely to the mapping of the position of the heavenly bodies in the sky in a particular place at a particular time.
From the Middle Ages onward the mapping of the heavenly bodies was generally represented by a figure made up of three squares, each inscribed within the other (in the sixteenth century a different form of visualization, made up of a circle and some lunettes, became a fashionable albeit less common alternative) (figures 1 and 2). While the central square contained vital information for the casting of horoscopes such as the name and place, day, and time of birth of a client, or the place and time of an event, the twelve equilateral triangles that framed the central square divided the horoscope in “houses,” each with a specific meaning and quality. In astrology, the houses represent sections of the ecliptic plane, the circle on the celestial sphere representing the sun’s apparent path throughout the year. The constellations of the zodiac (and the corresponding astrological signs) are distributed along a nine-degree band on either side of the ecliptic. The intersection of the ecliptic with the eastern horizon marks the cusp of the first house, called the ascendant (also called the degree of the horoscope), followed by the other houses moving counterclockwise. There was a wide range of methods that could be adopted to calculate house divisions, including the very popular system of the tenth-century Arab astrologer Alcabitus (al-Qabīṣī, d. AD 967), and the less popular one of equal houses suggested by the Latin writer and astrologer Julius Firmicus Maternus (fourth century AD), which was later adopted by the Renaissance *polymath Girolamo Cardano (1501–76). A lively debate ensued in the Renaissance about the preferred method of house division, as different methods, clearly, led to different interpretations of the chart.
Figure 1. Horoscope of Emperor Maximilian II, August 1, 1527 (square). Johannes Garcaeus, Astrologiae methodus (Basileae: Ex Officina Henricpetrina, 1576), n.p. Biblioteca Nacional de Espana.
Figure 2. Horoscope of Emperor Maximilian II (round). Johannes Garcaeus, Astrologiae methodus (Basileae: Ex Officina Henricpetrina, 1576), n.p. Biblioteca Nacional de Espana.
Within the triangles representing the twelve houses, the astrologer mapped the degree and sign of each cusp as well as the precise location of the heavenly bodies by sign and degree. In order to plot planets and stars within the horoscope, astrologers rarely relied on direct observation. Rather, from an early time, astronomers produced tables of houses indicating the zodiacal locations of the house cusps and tables of ephemerides providing the positions of the planets by calendar date and time of day. The use of these tables and basic mathematical computation allowed astrologers to determine the positions of the stars and planets for a particular place and time to be transferred onto a horoscope chart.
The interpretation of this celestial information is based on the basic principle not only that the stars and planets exerted a distinctive influence over the world below, but also that they interacted and influenced one another in specific ways. The interpretation of the astrologer’s chart thus centered on a complex web of relationships between the planets and the luminaries (the Sun and the Moon), the signs of the zodiac in which these were placed, and their astrological houses. A further element was that of the angular relationships between the planets, the so-called aspects, which determined their reciprocal influence, which could be positive, neutral, or negative.
This specific set of data, and the complex rules of interpretation that accompanied it, constituted the raw material of the astrologer, whose skill was to translate celestial information into a meaningful narrative that could explain or predict things as varied as the character and physical complexion of a person, major life events such as illnesses or professional successes and setbacks, the length of a person’s life, or, alternatively, determine the most favorable moment to undertake an action. The latter practice, called elections, had a distinctly Arabic pedigree and was very popular in the Renaissance, especially among the elites. Elections were often used to choose the most propitious time for the celebration and consummation of a marriage, for initiating warfare, to start a journey, or to place the foundation stone of a building. Thus people, but also cities and buildings, had their own horoscopes, each telling a specific story and each worthy of analysis, interpretation, and reinterpretation (figure 3).
It is no exaggeration to say that horoscopes were gold mines of information related to the event that the astrologer set out to investigate. While individuals’ birth charts (also called genitures) remained the most popular form of horoscope, there was no limit to what the astrologer could investigate. To this effect, we have ample evidence that buildings and cities possessed horoscopes. Historical reports by the Muslim geographer and historian Aḥmad al-Yaʿqūbī (d. 897 CE) and the polymath astronomer Aḥmad al-Bīrūnī (973–1050 CE) preserve written “horoscopes” for Baghdad and al-Mahdiyya in Tunis, with al-Bīrūnī adding the actual chart of Baghdad, on the basis of which, it was said, astrologers had incorrectly predicted that no caliph would ever die in that city. The death of two caliphs, al-Amīn (d. 813) and al-Mutawakkil (d. 861), in the city later gave ample ammunition to the detractors of astrology, who often cited these cases to cast doubt on the discipline.
Buildings, much like cities, also merited horoscopes, a practice that is documented both for medieval Islam and for Renaissance Italy. It is significant to notice that both the Roman architect Vitruvius and the Renaissance architect and polymath Leon Battista Alberti included astronomical and astrological concepts in their architectural texts. Vitruvius openly instructed the architect to understand the heavens in order to choose the best site in which to situate a building as, he believed, celestial influence would determine the optimal or suboptimal characteristics of the edifice. Similarly, Alberti referred to the radiation of the stars when discussing how to choose a healthy site, placing particular importance on the moment when construction commenced. Following these principles, Pope Julius II founded the new St. Peter’s Basilica on a specific day and at a specific time, more precisely on April 18, 1506, at 10:00 a.m., in a clear attempt to coordinate Heavens and Earth and refound the church at the most auspicious time (figure 4). Julius apparently chose a date that had a profound meaning for the original edifice, which was founded by Constantine on the movable feast Sabbato in albis, the first Saturday after Easter. The same feast in 1506 fell on April 18, thus marking the ritual rebirth of the most important church of Christianity. While the date could not be chosen astrologically, the time was selected carefully to make the cardines of the chart (the cusps of the four angular houses, which are the most powerful) coincide with those of the birth horoscope of Christ. The planet Mercury, generally associated with Christianity, moreover, was placed in the powerful tenth house, or Midheaven, together with the benevolent Sun and Venus. The foundation horoscope, moreover, correlated with the pope’s own birth horoscope, thus creating an ideal set of celestial relationships between Christ, St. Peter’s, and Julius’s birth chart.
Figure 3. Horoscope of the foundation of Byzantium, May 2, 638. Luca Gauricus, Tractatus astrologicus (Venice: Bartholomaeus Caesanus, 1552), fol. 2r. Bibliothèque nationale de France.
Years later, when the construction of the basilica was floundering, the Neapolitan astrologer Luca Gaurico proposed a rectified chart that placed the time at 9:21 a.m. Mercury was still favorably placed in the tenth house, but Jupiter, the benevolent planet that was originally in the second house, that of wealth, had moved to the third house, that of siblings. This, for Gaurico, represented one factor that could explain why the construction of St. Peter’s had stalled.
Together with birth, death was also a common object of investigation. It was not unusual for astrologers to be asked to calculate the duration of life of a client or a client’s enemy. Numerous cases can be documented for the Renaissance, the most notorious of which was probably that of another pope, Urban VIII, whose death was predicted astrologically in 1630. The rumor mill generated by this prediction came to an abrupt end when the pope ordered the incarceration of those whom he deemed responsible, and particularly of the unfortunate Orazio Morandi, the abbot of the convent of Santa Prassede in Rome, who was deemed responsible for fueling the rumors. The case generated abundant documentation and was punctuated by the unfortunate and rather suspicious death of Morandi only a few months into the trial.
Figure 4. Horoscope of the new foundation of St. Peter’s Basilica under Julius II, April 18, 1506. Luca Gauricus, Tractatus astrologicus (Venice: Bartholomaeus Caesanus, 1552), fol. 6r. Bibliothèque nationale de France.
As this brief series of examples illustrates—and many more could be cited—horoscopes were used as sources of valuable information. As maps of the past, present, and future open to interpretation and reinterpretations, horoscopes constituted crucial sources of information that required skillful interpretation, but this process of interpretation was not necessarily completely reliable, let alone without risk. As the Morandi case demonstrates, making sensitive astrological information publicly available to third parties had the potential of having practical repercussions for those who manipulated this information for their own ends and handled it inappropriately.
Monica Azzolini
See also diagrams; error; forecasting; learning; maps; observing; teaching
FURTHER READING
- Monica Azzolini, The Duke and the Stars: Astrology and Politics in Renaissance Milan, 2013; Tamsyn Barton, Ancient Astrology, 1994; Brendan Dooley, Morandi’s Last Prophecy and the End of Renaissance Politics, 2002; Anthony Grafton, Cardano’s Cosmos: The Worlds and Works of a Renaissance Astrologer, 1999; Darin Hayton, The Crown and the Cosmos: Astrology and the Politics of Maximilian, 2015; Mary Quinlan-McGrath, Influences: Art, Optics and Astrology in the Italian Renaissance, 2013; Michael Ryan, A Kingdom of Stargazers: Astrology and Authority in the Late Medieval Crown of Aragon, 2011; George Saliba, “The Role of the Astrologer in Medieval Islamic Society,” Bulletin d’études orientales 44 (1992): 45–67.