[citation needed] He soon expanded the region under his control to the eastern mountain valleys,[citation needed] capturing Lara,[3] where a castle was built, thus extending his rule from the foot of the Cantabrian Mountains around Espinosa de los Monteros to the river Arlanza.

[citation needed] In order to extend his territory this far, he first had to displace the Muslims based at the stronghold of Carazo that dominated the area and access.

[citation needed] In 912, he took the lead role in the Castilian offensive to the river Duero, settling the old villages of Haza, Clunia and San Esteban de Gormaz.

Modern scholars suspect that he must have been in disgrace at court for some unrecorded mistake or other major offense typically resulting in exile, as somebody with his name and the then seldom given rank of count — Gundisalvus comes — appears signing royal documents at the court of Navarre between 924 and 930, the year that his son was given the authority of count alone.

[citation needed] Previously, his wife Muniadonna,[1] who seems to have been a member of the Asturian royal family, appears holding the patrimony estates and county regency during the minority of their son Fernán.