In 1247, the Christian King Ferdinand III of Castile and León began the conquest of Andalusia. After winning Jaén and Córdoba, seized from the surrounding villages, as Carmona, Alcalá del Río Lora del Río, placing the army in the vicinity of the city. The siege lasted for fifteen months. The decisive action took place in May 1248, by Ramón de Bonifaz, who sailed up the Guadalquivir, breaking the bridge connecting Seville and Triana and allowing the supply of the city through Aljarafe. The city surrendered on November 23, 1248.
While there was no permanent capital (Burgos and Toledo disputed the priority, but the royal residence and the court were traveling), from the time Seville was one of the cities most frequently lodged with the court. On May 30, 1252, King Ferdinand III died at the Alcazar, the first being his body was buried in the building, formerly used as a mosque and then a cathedral, under an epitaph Quadrilingual (Latin, Castilian, Arabic and Hebrew) that lived up to his nickname King of the three religions. Fernando III the Saint was canonized in 1671 and his feast day, May 30, is a local holiday in Seville, to be their patron saint.

During the reign of Alfonso X the Wise, Seville was one of the capitals of his kingdom, since the capital was rotated between the cities of Toledo, Murcia and Seville. At this time built the parish of Santa Ana in Triana, the Gothic Palace of the Royal Palaces and the Tower of Don Frederic. In 1253 the king founded a General or university study, which had no continuity, so the current University of Seville is considered founded in 1505. Moreover, the monarch is buried at the Chapel Royal of the cathedral church where the relics are also known as Alphonsine Tables (not to be confused with the eponymous book). Also are vintage images alfonsí Marian de la Virgen de los Reyes and the Virgin headquarters. In addition, several Cantigas de Santa María mention the city and the Kingdom of Sevilla.
The following reigns, from that of Alfonso X the Wise to that of Peter the Cruel were habitual presence of the court in Seville. Alfonso gave the city its emblem (NO-hank-DO for their loyalty during the rebellion of his son Sancho). During that time he undertook numerous church buildings, but not the works of the cathedral began in 1433.
The Battle of Salado (1340) was the opening of the Strait of Gibraltar naval trade between southern and northern Europe and a growing presence of Italian and Flemish merchants in Seville, key to the integration of the southern routes Crown of Castile on those routes. The Black Death of 1348, the great earthquake of 1355 (which caused casualties and serious damage to many buildings) 7 and the demographic and economic crisis of the fourteenth century affected the city in a very pronounced. The worsening of social conflicts found a loophole in the anti-Jewish riot in 1391, raised by the anti-Semitic preachings of the archdeacon of Ecija, Ferrán Martínez. The Jewish quarter of Seville, one of the largest Jewish communities of the peninsula, virtually disappeared during the killings and the mass conversions. Since then the community is talking of the new Christians that will inherit the condition as a scapegoat.
During a stay of the Catholic Monarchs in Sevilla (1477) that, at the request of the Dominican Seville Alonso de Ojeda, was promoted the founding of the Spanish Inquisition. The city was chosen for the first auto de fe (February 6, 1481), in which six people were burned alive. After the discovery of America the city became the economic capital of the Spanish Empire.