Castilla, Spanish for Castile, “the land of castles” is first used in about 800 AD for a small area under the Cantabrian Mountains. Castile expanded in the 9th century but remained a collection of counties, whose rulers were nominated by the kings of Asturias and Leon. This all changed in 970 when Fernan Gonzalez united all the counties and became the first count of all Castile.

The Beginning

Sancho III Garces (the Great) who was already in control of the counties of Aragon, Sobrarbe and Ribagorza, conquered the county of Castile and seized the city of Leon. He took the title of emperor in 1034 but died the next year. He gave the territory to his son. The Kingdom of Navarre was assigned to Garcia III (1035-1054), Aragon to Ramiro I (1035-1063) and Castile to Ferdinand I (1035-1065). Each of the brothers took the title king. After Sancho III’s death, Bermudo III covered Leon, but Ferdinand I killed him in 1037 and took possession of the kingdom of Leon. He overpowered his brothers, triumphing on the battlefield, capturing Coimbra and pushing back the Muslim rulers of Toledo, Sevilla and Badajoz. Ferdinand I followed his father’s example and divided the territory among his sons. Sancho II (1065-1072) received Castile and Alfonso VI (1065-1109) received Leon. After the murder of Sancho II in 1072, Alfonso VI took over the kingdom of Castile. In 1085 the Muslim kingdom of Toledo in Spain had been annexed by Castile. Alfonso VII (1126-1157) divided the kingdom once again between his sons Sancho III (1157-1158), who received Castile and Ferdinand II (1157-1188), who received Leon.

The reign of Sancho III was very short; he was succeeded by Alfonso VIII of Castile (1158-1214). He and Alfonso VIII of Aragon signed a treaty in 1179 dividing the territories of Muslim Spain they were planning to conquer. Castile retained the right of conquering Andalusia and Murcia. However the conquest didn’t go so easy. Alfonso VIII of Castile suffered a terrible defeat by the Almohads in 1195 at Alarcos, south of Toledo. Although before the defeat Alfonso provoked the other Christian rulers and was not in good terms with them, the defeat opened their eyes of the threat that Almohads’ presented for them. Alfonso VIII of Castile collaborated with Sancho VII of Navarre (1194-1234), Peter II of Aragon (1196-1213) and Portuguese and Leonese troops, and in 1212 triumphed over the Almohads at Las Navas de Tolosa, which marked the beginning of the end of the Almohad Empire. After the death of Alfonso IX of Leon (1188-1230), he was succeeded by his son Ferdinand III, who was already a king of Castile (1217-1252). The reason he became king of Castile was his mother, Berenguela, daughter of Alfonso VIII. With this, Castile and Leon were permanently united. Ferdinand III conquered Cordoba in 1236, Murcia in 1243, Jaen in 1246 and Sevilla in 1248. The only Muslims state was Granada, and even they were obligated to pay a tribute to Castile.
As the kings of Castile grew in power, the nobility tried to abuse the institutions of government for their own interests. This struggle for power commenced during the reign of Alfonso X the Wise (1252-1284), who is best known for the literary and scientific achievements under his direction by scholars whom he summoned at court. He tried to gain control over the Moroccan ports that were giving access to the Iberian Peninsula, but this provoked a revolt in Granada. He was elected a Holy Roman Emperor in 1257. Alfonso X concluded that a royal law was needed to replace the multiplicity and diversity of the local and regional laws. In 1254, the Especulo, a code of law intended for use in the royal court and the Fuero Real, a code of municipal law meant for the towns of Castile and Extremadura was promulgated. Between 1256 and 1265 the Especulo was revised under heavy Roman law influence and was later known as the Siete Partidas (Seven Divisions).

In 1275, the oldest son of Alfonso X and the heir, Fernando de la Cerda died while trying to repel a Moroccan invasion. A dispute broke out about the succession between the son of Fernando de la Cerda, Alfonso and the kings’ second son, Sancho. Alfonso X recognized Sancho as heir, and in 1282 an assembly of nobles transferred the responsibilities of government from the king to Sancho. This resulted in a civil war that lasted till 1284.

Sancho IV (1284-1295) still had a strong opposition from supporters of his nephew Alfonso. At the same time, he had to defend against another Muslim invasion. Alfonso tried again to take the crown from Ferdinand IV (1295-1312) but he finally gave up all claims to the Crown of Castile in 1304. In the time of reign of Alfonso XI (1312-1350) new attempts for disorder were made from the nobility, but after reaching adulthood, Alfonso XI brutally crushed his enemies. With help from the Christian neighbors, he crushed the allied Islamic forces from Granada and Morocco at the battle of Salado River in 1340. With this battle ended the Moroccan attempts for conquest in Spain. Four years later he managed to capture Algeciras, but fell victim to the Black Deaths before he could take Gibraltar.

Conflicts broke out again in time of Peter the Cruel (1350-1369). Henry of Trastamara, half brother to Peter, contested his right to rule, and asked France for support. With the help of the French mercenary army led by Bertrand du Guesclin, Henry ejected Peter from the kingdom in 1366. Peter asked for help from Edward, Prince of Wales, and from the combined Anglo-Castilian army, and defeated Henry at Najera in 1367. Edward withdrew afterwards, but Henry and Bertrand again defeated and killed Peter at Montiel in 1369.

Henry II (1369-1379) established the Trastamara dynasty. He defeated his enemies and secured his throne. His son, John I (1379-1390) acknowledged the Pope Avignonese. He tried to invade Portugal in 1385 but was defeated at Aljubarrota. Later, John of Gaunt, duke of Lancaster and husband of Peter’s first daughter tried to take the Castile thrown with the help of the Portuguese, but married his daughter to John I’s son – Henry III (1390-1406) in 1388. In the time of John II (1406-1454) and Henry IV (1454-1474), the nobles were struggling to gain influence over the king. Henry IV recognized his sister Isabella as heir. In 1469 she married Ferdinand, son and heir of John II of Aragon. Hangry IV tried to exclude her from the succession, but after his death Isabella was proclaimed Queen Isabella I (1474-1504). In 1479 Ferdinand took the throne of Aragon, and brought a personal union of Aragon and Castile.