In 1236 Ferdinand III of Castile took Córdoba, the former capital of the Umayyad caliphate — a conquest of huge symbolic weight that turned its Great Mosque into a cathedral.
The Conquest of Córdoba in 1236 was the capture of the old Umayyad capital by Ferdinand III of Castile. For the Christian kingdoms it was a prize charged with symbolism: the city that had once ruled al-Andalus as a caliphate now fell to Castile.
The conquest turned the Great Mosque of Córdoba into a Christian cathedral and opened the rich Guadalquivir valley to further advance. It was the first of Ferdinand III's great southern conquests, to be followed by Jaén and Seville.
Córdoba in the 1230s was a shadow of the caliphal metropolis of three centuries earlier, reduced to a weak taifa amid the collapse of Almohad power after Las Navas de Tolosa. The Guadalquivir cities were divided and could not combine.
Ferdinand III, ruling a Castile and León reunited under his crown from 1230, pressed south into this vacuum. When Castilian adventurers seized a suburb of Córdoba by night, the king marched to exploit the opening.
With part of the city already in Christian hands and no relief in prospect, Córdoba surrendered on terms on 29 June 1236. Its Muslim population largely departed, and the Great Mosque — one of the wonders of the medieval world — was consecrated for Christian worship.
Ferdinand had the bells of Santiago, which al-Mansur had famously carried off to Córdoba around 997 to hang as lamps in the mosque, returned to Compostela — closing a loop of memory that made the conquest resonate across Christian Iberia.