His letter dated 912 to the town of Brañosera confirmed the rights granted by his grandparents, whom he names [Becerro de Cardeña ]. Referred to as "comes in Burgos" in 899 [Pérez de Urbel]. He built the castle of Lara in 902, and populated Aza, Clunia and San Estebán in 912 [Pérez de Urbel]. He is last mentioned in Castile in 916 [Pérez de Urbel]. He may have been banished to Navarre from 920 to 930, a "Gundisalvus comes" witnessing royal Navarrese documents during this period [Pérez de Urbel], although if this is correct it is surprising that his wife did not accompany him, established as she was in the castle of Lara during that time. A "Gundisalvus Fredinandiz comes" witnessed a 932 donation, signing immediately after King Ramiro II and before "Fredenandus comes" (presumed to be Fernando González).