The year (1236) that Cordoba was recaptured from the Moors, by King Ferdinand III of Castile and rejoined Christendom, the mosque was reconsecrated a Christian church. Alfonso X oversaw the construction of the Villaviciosa Chapel and the Royal Chapel within the structure of the mosque. The kings who followed added further Christian features: Enrique II rebuilt the chapel in the 14th century.
The most significant alteration was the construction of a Renaissance cathedral nave in the middle of the structure. It was constructed by permission of Carlos V, king of united Spain. Its reversion to a Christian church (officially the Cathedral of the Assumption of the Virgin) may have helped to preserve it when the Spanish Inquisition was most active.
Artisans and architects continued to add to the existing structure until the late 18th century.