Alfonso X (November 23, 1221, Toledo, Spain – April 4, 1284, Seville, Spain) was a Spanish monarch who ruled as the King of Galicia, Castile and León from 1252 until his death. He was elected Rex Romanorum in 1254. His nicknames were "el Sabio" ("the Wise", more accurately translated "the Learned") and "el Astrólogo" ("the Astrologer").

Among the most important of the works by Alfonso X was the celebrated Cantigas de Santa Maria ("Songs to the Virgin Mary"), one of the largest collections of monophonic songs to survive from Medieval times. The Cantigas de Santa Maria consists of 420 poems written in Galician-Portuguese with musical…