Alcázar of Córdoba: View of the castle walls and one of the towers
The term derives from the Arabic word al-qasr meaning "fort, castle or palace"; the Arabic word comes from the Latin "castrum", meaning an army camp or fort. It was originally a Visigothic fortress. Abd al-Rahman II (reigned 822-852) enlarged Córdoba's Alcázar and built an aqueduct to supply the city with drinking water. Abd Allah (reigned 888-912) also expanded the Alcázar. Córdoba was reconquered from the Muslims by Ferdinand III of Castile (reigned 1217-1252) in 1236. His son, Alfonso X, began work on a new palace, the site of the Alcázar Nuevo (altered). The Alcázar was expanded to a very large compound with baths, gardens, and the largest library in the West. Watermills on the nearby Guadalquivir river powered water lifting to irrigate the extensive gardens.