Simon Doubleday

Astrolabe

Alfonso’s fascination with the stars followed the model of earlier Muslim-Spanish rulers; in the eleventh century, the kingdom of Toledo had been a hub of medieval science. At the court of Al-Mamun (r. 1043-73) in Toledo, Ibrahim ibn Said produced two brass celestial globes, and the astronomer Al-Zarqali ( ‘Azarquiel’ to Christian Spaniards) refined the astrolabe.

For centuries, Alfonso’s name was associated with the works of astronomy produced at his court or under his patronage. The most widely known was the Alfonsine Tables: a set of data revising the work of al-Zarkali, an eleventh-century Muslim astronomer from Córdoba, on the basis of observations taken in Toledo between 1263 and 1272.

The astronomers who produced the Alfonsine Tables—one of the king’s great legacies to Renaissance Europe—presented the king’s accession to the throne as the dawn of a new age, the ‘Alfonsine era.’ “Our king, Don Alfonso”, they wrote, “outdid all other wise kings in knowledge, intelligence, and understanding, justice, goodness, piety and nobility”.