[1] He succeeded his uncle Pedro, whose episcopate, and life, had ended in exile after the Battle of Candespina (1111).
[3] Diego spent much of his episcopate repairing his diocese from the damage wrought by the civil war between the supporters of Queen Urraca and Alfonso the Battler.
"[1] He continued his uncle's struggle for independence from the archdiocese of Toledo, at which he was not initially successful.
In 1125 Honorius II confirmed it, but by 1130 Diego had succeeded in getting this decision reversed and regained his prior exemption.
He was deposed by a synod held in Carrión de los Condes in 1130, probably at the instigation of his Toledan opponents.