ألفونسو السادس ملك قشتالة
Burgos became a bishopric in 1075 by the king Alfonso VI of León and Castile "the Brave" on authority of Pope Gregory VII, giving it a canonical continuation with the episcopal tradition of the diocese of Oca, whose prelate was in 589 already recorded as a signatory to the Third Council of Toledo during the reign of the Visigoths.