First count independent of Castile whose date of birth is unknown (probably born in Burgos) and who died in the 970. Son of Gonzalo Fernández, repopulation of Clunia and Lara, and Muniadonna.
To 931 had managed to unify under its authority counties such as Burgos, Alava, Lara, etc., which were later forming the great Castilian County, even to expand until Sepulveda which was repopulated in 940.
Aware of its power and what was popular opinion, he maintained an independent attitude towards the Kingdom of Leon, so Ramiro II, jailed it in the year 944 in Leon, as well as remove all its titles.
But the insistence of the Caliph Abd al-Rahman III, who then had major armies, made that the Leonese King free him, and married the infante Ordoño, who would later become Ordoño III, Doña Urraca, daughter of the count. At the death of Ramiro II in the year 951, occurred the true independence of Castile, even with Fernán González intervention in Leonese domestic policy. The support given to his son-in-law Ordoño III, to take the throne to Sancho the Crassus, in the year 958, resulted in a civil war, which was attended by Muslim, they achieved the objectives of Fernán González and Navarre.
He died in June of the year 970, and his son García Fernándezsucceeded him peacefully. The great achievement of Fernán González was made hereditary title of count, thus unifying Castilla. Character epic, appears in many Castilian literary works, which are founded on history, especially the poem of Fernán González.