Mosque–Cathedral of Córdoba is a Catholic Christian cathedral and formerly a medieval Islamic mosque.
The building was begun around the year 600 as the Christian Visigothic church of St. Vincent.
After the arrival of Islam to the Visigothic kingdom, the church was divided between the Muslims and Christians. When the exiled Umayyad prince Abd ar-Rahman I escaped to Spain and defeated the Andalusian governor Yusuf al-Fihri, he allowed the Christians to rebuild their ruined churches, and purchased the Christian half of the church of St. Vincent. Abd al-Rahman I and his descendants reworked it over two centuries to refashion it as a mosque, starting in 784. Additionally, Abd al-Rahman I used the mosque (originally called Aljama Mosque) as an adjunct to his palace and named it to honor his wife. Traditionally, the mihrab of a mosque faces in the direction of Mecca; by facing the mihrab, worshipers pray towards Mecca. Mecca is east-southeast of the mosque, but the mihrab points south.
The mosque underwent numerous subsequent changes: Abd ar-Rahman II ordered a new minaret, while Al-Hakam II, in 961, enlarged the building and enriched the mihrab. The last of the reforms was carried out by Al-Mansur Ibn Abi Aamir in 987. It was connected to the Caliph's palace by a raised walk-way, mosques within the palaces being the tradition for the Islamic rulers of all times. The Mezquita reached its current dimensions in 987 with the completion of the outer naves and courtyard.
The building is most notable for its arcaded hypostyle hall, with 856 columns of jasper, onyx, marble, andgranite. These were made from pieces of the Roman temple which had occupied the site previously, as well as other destroyed Roman buildings, such as the Mérida amphitheatre. The double arches were a new introduction to architecture, permitting higher ceilings than would otherwise be possible with relatively low columns. The double arches consist of a lower horseshoe arch and an upper semi-circular arch. The famous alternating red and white voussoirs of the arches were inspired by those in the Dome of the Rock. and also resemble those of the Aachen Cathedral, which were built almost at the same time. A centrally located honey-combed dome has blue tiles decorated with stars.
The mosque also has richly gilded prayer niches. The mihrab is a masterpiece of architectural art, with geometric and flowing designs of plants. Other prominent features were: an open court (sahn) surrounded by arcades, screens of wood, minarets, colourful mosaics, and windows of coloured glass. The walls of the mosque had Quranic inscriptions written on them.
In 1236, Córdoba was captured by King Ferdinand III of Castile in the Reconquista, and the mosque was turned into a Catholic church. Alfonso X oversaw the construction of the Villaviciosa Chapel and the Royal Chapel within the mosque. The kings who followed added further Christian features, such as King Henry II rebuilding the chapel in the 14th century. The minaret of the mosque was also converted to the bell tower of the cathedral. It was adorned with Santiago de Compostela’s captured cathedral bells.
The most significant alteration was the building of a Renaissance cathedral nave right in the middle of the expansive structure. The insertion was constructed by permission of Charles V, king of Castile and Aragon.
The Great Mosque's conversion to a Christian Catholic church, the Catedral de Córdoba, 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.