Ferdinand III, king of Castile from 1217, inherits the neighboring kingdom of León at the death, in 1230, of his father, King Alfonso IX, and unites the two states as the kingdom of Leon and Castile.

A Christian zealot known as “the Saint,” Ferdinand inaugurates a military crusade to destroy the Moors in southern Spain.

The extensive effects of the Almohads' defeat by the Christians at Las Navas de Tolosa do not become apparent until after 1233, when their empire disintegrates owing to dynastic squabbles, and the Muslim hold on Spain, lacking a central leader, slips rapidly before the armies of the Christian reconquest.

During Almohad domination, the city of Córdoba has declined, the role of the capital of Muslim al-Andalus having been given to Seville.

Ferdinand has sent his forces against Moorish strongholds in the Guadalquivir River valley, besieging Córdoba.

After a siege of several months, it falls on June 29, 1236, to Ferdinand, who imposes Christian culture on Córdoba without destroying the city’s great Moorish landmarks.

Córdoba’s notable Great Mosque, called the Mezquita, will eventually become a cathedral.

The city is divided into fourteen colaciones, and numerous new church buildings will soon be added.

The autonomous Muslim kingdom of Murcia submits during the campaigns of Ferdinand III,  almost without a struggle, to his son Alfonso; Ferdinand incorporates the province into the kingdom of Castile in this year.

Ferdinand III besieges and captures the Moorish stronghold of Jaén, in eastern Andalusia, in 1245-46.

The Muslim kingdom of Granada, founded early in the thirteenth century out of the remnants of Almoravid power in Spain, comprises, principally, the area of the modern provinces of Granada, Málaga, and Almería.

Its founder, Abu 'Abd Allah ibn Yusuf ibn Nasr al-Ahmar, who had in 1238 become king, as Mohammad I, in 1246 secures the recognition of Ferdinand III of Castile, his neighbor on all landed frontiers, in return for a vassalage.

Ferdinand III besieges and captures the Moorish stronghold of Seville, the capital of al-Andalus, in 1248.

Following their victory, the Spanish Christian conquerors evict the defeated Moorish inhabitants from their homes, and assume control of vast estates.

(The eventual result of this act, perpetrated for the first time in Muslim Spain, will be economic ruination in the region.)