Ethelred the Pious
Castile was the most powerful Christian kingdom of 10th-century Spain. Its chief city was Burgos. The kingdom was an important Christian political and military center until its conquest by the Moorish taifa of Nawar in 1035.
In 950, Castile emerged as the strongest independent Christian kingdom in Spain. Galicia had been overrun by the Vikings and León by the Moors. But that year, Ferdinand defeated an army from Córdoba at the Battle of Lena (in Asturias). In the 970s, the Caliphate conquered most of the Pyrenees, founding the city of Al-Darra and converting most of the Basques to Islam, effectively surrounding Castile. At the same time, the Viking rulers of Galicia embraced Christianity and built their conquest into the dynamic Kingdom of St. John. Córdoba encouraged a civil war in the 980s, which weakened Castile and reduced it to vassalage until 1002.
In the early 1000s, Galicia/St. John and Castile forged a close alliance, leading to a union of crowns in mid-century. This kingdom, uniting all of Christian Spain, vigorously expanded to the southwest where Moorish control was weak, but it was checked in the east along the Castilian frontier. The Emirate of Nawar (Navarre) overran all of Castile and tore down the walls of Burgos. Asturias remained part of the Kingdom of St. John.
Thereafter, Castile was a part of the Muslim world of Al-Andalus, but the population always remained heavily Christian. The King of St. John continued to use "King of Castile" as part of his royal title; the title is connected with the Crown of Asturias.
929: Proclamation of the Caliphate
Ferdinand González (930–970)
- 939: Battle of Simancas, Muslim victory
- 942: Fall of Leon (Ferdinand's feudal overlord)
- 949: Viking conquest of Galicia (Galisja)
- 950: Ferdinand defeats Caliph's armies, takes title King of Castile and Asturias
- 953: marries daughter to Count of Aragon
Garcia Fernandez (970-995)
- 974: Expands Castile's knighthood
- 976: Vizier Al-Mansur comes to power in Cordoba
- 964: Aids Hrut of Galisja in driving the English out of Compostela
- 990: Son rebels with Al-Mansur's support; rule essentially confined to Asturias
Sancho Garcia (995-1017) - married Astrid, daughter of King Hrut of Galisja and a descendant of Ragnar.
- 995: Reunites Castile and tacitly repudiates Al-Mansur
- 997: Al-Mansur lays siege to Burgos; Sancho agains submits to his overlordship
- 1002: Death of al-Mansur; Castile again independent
Alfonso Sanchez (1017-1036)
- 1020: Union with Galicia/Santiago
- 1031: Breakup of the Caliphate
- 1033: War begins against Nawar
- 1035: Nawar overruns Castile and captures Burgos
- 1036: King Alfonso captured, killed in captivity soon after. End of the Kingdom of Castile.