In 1247, the Christian King Ferdinand III of Castile and Leon began the conquest of Andalusia. After conquering Jaén and Córdoba, he seized the villages surrounding the city, Carmona Lora del Rio and Alcalá del Rio, and kept a standing army in the vicinity, the siege lasting for fifteen months and causing havoc in the local population. The decisive action took place in May 1248 when Ramon Bonifaz sailed up the Guadalquivir and severed the Triana bridge that made the provisioning of the city from the farms of the Aljarafe possible. The city surrendered on 23 November 1248.