The eldest son of Ferdinand III and Beatrice of Swabia, Alfonso was born in Burgos, in what is now northern Spain, on November 23rd, 1221. He grew up in the cultured220px-Alfonso_X_el_Sabio_(José_Alcoverro)_01 and cosmopolitan city of Toledo. He enjoyed the company of scholars and learned men, of all religions.  As heir to the throne, or infante, Alfonso was expected to learn the ways of kingship and his father King Ferdinand commissioned a book for him, on how to be a good king, ‘The Book of the Twelve Wise Men‘.

King Ferdinand was a great warrior king and Alfonso spent much of his youth with the royal army, as his father re-conquered large parts of Al Andalus from the Moors. In 1248 he played an important role in his father’s capture of Sevilla. The following year he married Yolant, called ‘Violante’, daughter of James I of Aragon, another Spanish Kingdom in the North. She bore him ten children.

Alfonso became king in 1252. Like his father before him, he attempted to increase 220px-TumboAKingthe territory of the crown, fighting the Portuguese over the Algarve frontier posts and claiming territory  in what is now southern France.  He also tried to gain the crown of the Holy Roman Empire, which he claimed by right of his German mother, but to no avail ( successive Popes did not support his claim, although it was a fair one ).

Perhaps Alfonso’s greatest legacy was the Siete partidas (Seven Divisions of the Law). This work is a discourse on various kinds of law, covering all aspects of social life. It was not put in place during Alfonso’s life-time, but his great grandson ensured that it became part of Spanish law and thence the law of Spain’s overseas possessions. As such, it had enormous influence on the future course of law in Latin America and 170px-Monument_to_Alfonso_X_El_Sabio,_La_Puebla_del_Riothe southern states of the U.S.A.. As recently as 1820 the Divisions were in daily use in Louisiana.

King Alfonso is honoured by a scupture as ‘The Law-giver’ on the U.S.Capitol. He is frequently shown, in paintings and statues, like the one shown left, as receiving the petitions of the poor or giving help to supplicants.

Alfonso was also a great patron of science. The scientific treatises compiled under his patronage were the work of the ‘School of Translators of Toledo’, an informal grouping of Christian, Muslim, and Jewish scholars who made available the findings of Arab science to Europeans in Latin and Spanish translations. In this way, copies of the works of the great classical scholars, like Plato and Aristotle, which had been preserved and translated into Arabic in Damascus, were once again available in the West and formed part of the basis for the eventual western Renaissance.

The King’s own main scientific interests were astronomy and astrology. He commissioned the Tablas Alfonsies (Alfonsine Tables), containing diagrams and figures on planetary movements, and the Libros del saber de astronomia (Books of Astronomical Knowledge), describing astronomical instruments. We know that the Tables were used by Copernicus and, later, by Galileo, when they carried out their observations and constructed the theory of how the earth and the other planets went around the sun – the solarcentric universe.  Copies of the Tables belonging to each of them still exist, including the notes they made within them. The lunar crater  Alfonsus was named in his honour.

Alfonso also commissioned two histories, the Primera crónica general (First 250px-LibroDesJuegasAlfonXAndCourtGeneral Chronicle) and the General estoria (General History).  The latter drew together previous ancient works, including the Old Testament and the myths and legends of ancient Greece, Egypt and Rome.  He also had translated ( and added to ) the ‘Libro de los Juegos‘ or ‘Book of Games’, the first treatise on games and game theory.

Of Alfonso’s poems, the most significant are those in the song cycle Cantigas de Santa Maria (Canticles of the Holy Mary), written between 1257 and 1279. The songs are written in the troubadour style and contain much descriptive detail about medieval life.  They were set to music, by Alfonso himself and are still performed to this day. Alfonso also wrote satirical and love poems.

80px-Coat_of_Arms_of_León.svgAlfonso’s eldest son, Ferdinand de la Cerda, supported his father and carried the prime burden of military leadership until Ferdinand’s death in 1275. This precipitated a lengthy struggle over the succession to the throne and Alfonso’s last years were clouded by the contest between supporters of his second son, Sancho, and those of his grandson Alfonso, the son of Ferdinand de la Cerda.  His family, including his younger brothers, took sides and the situation was exploited by the Barons and other aristocrats who wanted to gain more power for themselves.

In 1282 Sancho declared his father deposed. Alfonso disinherited Sancho and, 80px-Coat_of_Arms_of_Castile_(1390-15th_Century).svgbasing himself in Seville, called on his Moorish allies for help. Sancho prevented anyone from coming to his aid and Alfonso died in Seville, a tragic figure, on April 4th 1284, accepting that Sancho would succeed him, even as he cursed his name.