Ferdinand III of Castile Ferdinand III , T . O . S . F . , ( 5 August 1199 – 30 May 1252 ) was the King of Castile from 1217 and King of León from 1230 as well as King of Galicia from 1231 . He was the son of Alfonso IX of León and Berenguela of Castile . Through his second marriage he was also Count of Aumale . Ferdinand III was one of the most successful kings of Castile , securing not only the permanent union of the crowns of Castile and León , but also masterminding the most expansive campaign of Reconquista yet . By military and diplomatic efforts , Ferdinand greatly expanded the dominions of Castile into southern Spain , annexing many of the great old cities of al - Andalus , including the old Andalusian capitals of Córdoba and Seville , and establishing the boundaries of the Castilian state for the next two centuries . Ferdinand was canonized in 1671 by Pope Clement X and , in Spanish , he is known as " Fernando el Santo " , " San Fernando " or " San Fernando Rey " . Places such as San Fernando , La Union , San Fernando , Pampanga , and the San Fernando de Dilao Church in Paco , Manila in the Philippines , and in California , San Fernando City and the San Fernando Valley , were named for him and placed under his patronage . Early life . Ferdinand was born at the Monastery of Valparaíso ( Peleas de Arriba , in what is now the Province of Zamora ) in 1198 or 1199 . The marriage of Ferdinand ' s parents was annulled by order of Pope Innocent III in 1204 , due to consanguinity . Berenguela then took their children , including Ferdinand , to the court of her father , King Alfonso VIII of Castile . In 1217 , her younger brother , Henry I , died and she succeeded him to the Castilian throne , but she immediately surrendered it to her son , Ferdinand , for whom she initially acted as regent . Unification of Castile - León . When Ferdinand ' s father , Alfonso IX of León , died in 1230 , his will delivered the kingdom to his older daughters Sancha and Dulce , from his first marriage to Teresa of Portugal . But Ferdinand contested the will , and claimed the inheritance for himself . At length , an agreement was reached , negotiated primarily between their mothers , Berengaria and Teresa , and signed at Benavente on 11 December 1230 , by which Ferdinand would receive the Kingdom of León , in return for a substantial compensation in cash and lands for his half - sisters , Sancha and Dulce . Ferdinand thus became the first sovereign of both kingdoms since the death of Alfonso VII in 1157 . Early in his reign , Ferdinand had to deal with a rebellion of the House of Lara . Conquest of al - Andalus . Since the Battle of Las Navas de Tolosa in 1212 halted the advance of the Almohad s in Spain , a series of truces had kept Castile and the Almohad dominions of al - Andalus more - or - less at peace . However , a crisis of succession in the Almohad Caliphate after the death of Yusuf II in 1224 opened to Ferdinand III an opportunity for intervention . The Andalusian - based claimant , Abdallah al - Adil , began to ship the bulk of Almohad arms and men across the straits to Morocco to contest the succeession with his rival there , leaving al - Andalus relatively undefended . Al - Adil ' s rebellious cousin , Abdallah al - Bayyasi ( the Baeza n ) , appealed to Ferdinand III for military assistance against the usurper . In 1225 , a Castilian army accompanied al - Bayyasi in a campaign , ravaging the regions of Jaén , vega de Granada and , before the end of the year , had successfully installed al - Bayyasi in Córdoba . In payment , al - Bayyasi gave Ferdinand the strategic frontier strongholds of Baños de la Encina , Salvatierra ( the old Order of Calatrava fortress near Ciudad Real ) and Capilla ( the last of which had to be taken by siege ) . When al - Bayyasi was rejected and killed by a popular uprising in Cordoba shortly after , the Castilians remained in occupation of al - Bayyasi ' s holdings in Andújar , Baeza and Martos . The crisis in the Almohad Caliphate , however , remained unresolved . In 1228 , a new Almohad pretender , Abd al - Ala Idris I ' al - Ma ' mun ' , decided to abandon Spain , and left with the last remnant of the Almohad forces for Morocco . Al - Andalus was left fragmented in the hands of local strongmen , only loosely led by Muhammad ibn Yusuf ibn Hud al - Judhami . Seeing the opportunity , the Christian kings of the north - Ferdinand III of Castile , Alfonso IX of León , James I of Aragon and Sancho II of Portugal - immediately launched a series of raids on al - Andalus , renewed almost every year . There were no great battle encounters - Ibn Hud ' s makeshift Andalusian army was destroyed early on , while attempting to stop the Leonese at Alange in 1230 . The Christian armies romped through the south virtually unopposed in the field . Individual Andalusian cities were left to resist or negotiate their capitulation by themselves , with little or no prospect of rescue from Morocco or anywhere else . The twenty years from 1228 to 1248 saw the most massive advance in the Christian reconquista yet . In this great sweep , most of the great old citadels of al - Andalus fell one by one . Ferdinand III took the lion ' s share of the spoils - Badajoz and Mérida ( which had fallen to the Leonese ) , were promptly inherited by Ferdinand in 1230 ; then by his own effort , Cazorla in 1231 , Úbeda in 1233 , the old Umayyad capital of Córdoba in 1236 , Niebla and Huelva in 1238 , Écija and Lucena in 1240 , Orihuela and Murcia in 1243 ( by the famous ' pact of Alcaraz ' ) , Arjona , Mula and Lorca in 1244 , Cartagena in 1245 , Jaén in 1246 , Alicante in 1248 and finally , on 22 December 1248 , Ferdinand III entered as a conqueror in Seville , the greatest of Andalusian cities . At the end of this twenty - year onslaught , only a rump Andalusian state , the Emirate of Granada , remained unconquered ( and even so , Ferdinand III managed to extract a tributary arrangement from Granada in 1238 ) . Ferdinand annexed some of his conquests directly into the Crown of Castile , and others were initially received and organized as vassal states under Muslim governors ( e . g . Alicante , Niebla , Murcia ) , although they too were eventually permanently occupied and absorbed into Castile before the end of the century ( Niebla in 1262 , Murcia in 1264 , Alicante in 1266 ) . Outside of these vassal states , Christian rule could be heavy - handed on the new Muslim subjects . This would eventually lead to the mudéjar uprisings of 1264 - 66 , which resulted in mass expulsions of the Muslim populations . The range of Castilian conquests also sometimes transgressed into the spheres of interest of other conquerors . Thus , along the way , Ferdinand III took care to carefully negotiate with the other Christian kings to avoid conflict , e . g . the treaty of Almizra ( 26 March 1244 ) which delineated the Murcian boundary with James I of Aragon . Ferdinand divided the conquered territories between the Knights , the Church , and the nobility , whom he endowed with great latifundia s . When he took Córdoba , he ordered the " Liber Iudiciorum " to be adopted and observed by its citizens , and caused it to be rendered , albeit inaccurately , into Castilian . The capture of Córdoba was the result of a well - planned and executed process whereby parts of the city ( the Ajarquía ) first fell to the independent almogavars of the Sierra Morena to the north , which Ferdinand had not at the time subjugated . Only in 1236 did Ferdinand arrive with a royal army to take the Medina , the religious and administrative centre of the city . Ferdinand set up a council of " partidores " to divide the conquests and between 1237 and 1244 a great deal of land was parcelled out to private individuals and members of the royal family as well as to the Church . On 10 March 1241 , Ferdinand established seven outposts to define the boundary of the province of Córdoba . Domestic policy . On the domestic front , Ferdinand strengthened the University of Salamanca and erected the current Cathedral of Burgos . He was a patron of the newest movement in the Church , that of the mendicant Orders . Whereas the Benedictine monks , and then the Cistercian s and Cluniac s , had taken a major part in the " Reconquista " up until then , Ferdinand founded houses for friars of the Dominican , Franciscan , Trinitarian , and Mercedarian Orders throughout Andalusia , thus determining the future religious character of that region . Ferdinand has also been credited with sustaining the " convivencia " in Andalusia . He himself joined the Third Order of St . Francis , and is honored in that Order . Death . Ferdinand III had started out as a contested king of Castile . By the time of his death in 1252 , Ferdinand III had delivered to his son and heir , Alfonso X , a massively expanded kingdom . The boundaries of the new Castilian state established by Ferdinand III would remain nearly unchanged until the late 1400s . His biographer , Sister María del Carmen Fernández de Castro Cabeza , A . C . J . , asserts that , on his death bed , Ferdinand said to his son " you will be rich in land and in many good vassals , more than any other king in Christendom . " Ferdinand was buried in the Cathedral of Seville by his son , Alfonso X . His tomb is inscribed in four languages : Arabic , Hebrew , Latin , and an early version of Castilian . He was canonized as St . Ferdinand by Pope Clement X in 1671 . Today Saint Fernando can still be seen in the Cathedral of Seville , for he rests enclosed in a marvelous gold and crystal casket worthy of the king . His golden crown still encircles his head as he reclines beneath the statue of the Virgin of the Kings . Several places named San Fernando were founded across the Spanish Empire in his honor . The symbol of his power as a king was his sword Lobera . Family . First marriage . In 1219 , Ferdinand married Elisabeth of Hohenstaufen ( 1203 – 1235 ) , daughter of the German king Philip of Swabia and Irene Angelina . Elisabeth was called Beatriz in Spain . Their children were : Second marriage . After he was widowed , he married Joan , Countess of Ponthieu , before August 1237 . They had four sons and one daughter :