Alfonso X the Wise was a monarch very interested in promoting astronomy, because he wanted to know how the planets would influence his reign.
According to the historian of medieval science Julio Samsó, “the Wise King had an indisputable passion for astronomy, for which he has been described as the most prominent astronomer of the Christian Middle Ages. This interest was due, without a doubt, to the fact that, at his time, the stars were thought to exert a remarkable influence on the lives of human beings”.
Alfonso X was called the Star, because he had surrounded himself with a court of seers and stargazers.
The historian of science José Manuel Sánchez Ron tells that “the king had commented on occasions, both in public and in private, that if he had attended the creation of the world, the ordering of the heavens would have been done differently. He devoted so much time and energy to such tasks that a possible epitaph for the royal tomb circulated in his court: ‘While Alfonso contemplated heavenly things, he lost earthly things’”.
The king’s belief in astrology was reflected in the games, where the divination of the future by means of the stars was approved, “performed by those who have good knowledge of astronomy”. In addition, other forms of divination were prohibited and those who conjured evil spirits or made figures of wax, metal or other material with the aim of harming another person were punished with the death penalty.
Thus, astronomy was the main exponent of the scientific panorama during the medieval period. At that time, the terms astronomy and astrology exchanged their meanings and applications, becoming an indissoluble binomial. Both were part of the seven liberal arts in which the Wise King was interested.
Relying on the Toledo School of Translators, the monarch set up a group of Arab, Jewish and Christian scholars who, taking up the existing tradition in that city, searched for and retrieved the most important and influential Arabic texts, and updated and translated them. to Latin first and to Romance later, the astronomical knowledge accumulated since the time of Ptolemy.
The scientific works that are associated with the king were the result of the work of this group of scholars that he assembled at his court. At least fifteen such men have been identified as working at his court, most of them in astronomy. Alfonso X himself recognized in the General Estonia that his role in book production was not to write with his own hand, but rather to order the reasons why, how and what to write.
What we can call Alfonsine astronomy is condensed, in order of importance, in The Alphonsine Tables Y The Knowledge Books of Astrology.
The alphonsian tables
Made in Toledo between 1252 – the year in which Alfonso was crowned King of Castile – and 1272, the Boards They constitute an update of those of Azarquiel, which they quickly displaced from the 1320s. They studied the path of the Sun and contained the positions of the celestial bodies calculated according to the meridian of Toledo.
They also included results of observations and astronomical records, some ancient and others carried out by Alfonsine astronomers, rectifying and correcting stellar positions, the Sun, the Moon and the five planets known at the time (Mercury, Venus, Mars, Jupiter and Saturn). , solar and lunar eclipses, necessary information for the measurement of time, the duration of months and years, the establishment of calendars and the prediction of astronomical ephemerides.
The Boards have been pondered throughout history. The most recent example is found in CM Linton, who points out that “the most important product of the reign of Alfonso X was a set of astronomical tables, whose original text has been lost, but which were the basis of practically all astronomical calculations until the middle 17th century”.
The alphonsian tables were, therefore, known throughout Europe even after Copernicus, until they were replaced by the Rudolfine tables.
The astrology knowledge books
The title by which the other great astronomical work promoted by Alfonso X should be known, astronomy lore booksIt’s of astrology knowledge books. If this has not been the case, it is fundamentally due to the influence of the physicist, physician and bibliophile Manuel Rico y Sinobas, who published the Spanish translation, annotated and commented on in five volumes.
Following Sánchez Ron again, “the opinion that Rico and Sinobas had of astrology was anachronistic, and he tried to rid the work of Alfonso X of what he considered an approach that was as erroneous as it was harmful”.
The work, which follows Aristotelian thought, seeks expository clarity, highlighting the value of the image. Thus, in the prologue you can read “more than light knowledge, not only by understanding, even more by sight.”
It is organized in four parts, some of which have reached us incomplete due to the passage of time. The first, the Book of the figures of the stars that are fixed in the eighth heaven, contains a catalog of stars that constitute the constellations and the zodiac, incorporating stars and nebulae that do not appear in Ptolemy’s Almagest. It was not a mere translation, but data was added to it. The next two parts are dedicated to the astronomical instruments azafea and astrolabe. The fourth part is made up of five books dealing with the construction and use of sundials, water, sand, fire and mechanics.
The books, written in Spanish, were practically unknown in Europe in the years following their appearance, due to the difficulties of the language. They regained interest after being translated into Florentine at the request of the Italian merchant Federighi Guerruccio, on a trip to Seville in 1341.
Summing up, posterity has Alfonso X as the only scientific king in the history of Spain, to whom the transmission of astronomical knowledge to late medieval and Renaissance Europe is largely due. According to the distinguished French Hispanist Boudet, from Charlemagne to the Medici, no prince did as much as Alfonso X for civilization and science.