Background
Bermudo III was the son of Alfonso V of León by his first wife Elvira Menéndez. Bermudo married Jimena Sánchez, who was a daughter of Sancho Garcia of Castile.
Bermudo III was the son of Alfonso V of León by his first wife Elvira Menéndez. Bermudo married Jimena Sánchez, who was a daughter of Sancho Garcia of Castile.
He was called Emperor in Galicia in 1025. He succeeded to the throne of León in 1027. In 1029, Count García Sánchez of Castile was about to be married to Sancha of León, the elder sister of Bermudo, an arrangement apparently sanctioned by the king of Navarre, when the count was murdered in the city of León by the Velas, a party of Castilian nobles exiled from their own country, who had taken refuge in Leon.
Leon and Navarre disputed the succession to the Countship of Castile thus left vacant.
He seized the borderlands between the Cea and the Pisuerga rivers, right above León capital, long a bone of contention between León and Castile. In 1034, Sancho wrested the city of León itself from his brother-in-law, Bermudo, who retreated into Galicia.
By the time Sancho died in 1035, the meseta north of the Duero was dominated by the Pyrenean pocket kingdom of Navarre. However, for all of Sancho"s diplomatic and military skill, one cannot help but think that such a situation was essentially the fortuitous result of having youthful opponents.
After Sancho"s death, Bermudo III was immediately received back into León and soon began a campaign to recover from Castile and his brother-in-law Ferdinand, the disputed territory between the Cea and Pisuerga.
Bermudo III was killed at the Battle of Tamarón on September 4, 1037. Autopsy of his remains shows that he may have suffered death from infantry spears or pikes, after falling from his horse. From that time the hegemony which Leon had enjoyed began to pass to Castile.
The dynasty of Navarre had triumphed perhaps, but the united realm of León and Castile with its rimlands of Asturias and Galicia, had become the political center of the north Iberian Christian society.