Cresconius (Spanish: Cresconio) (c. 1036 – 1066) was an 11th-century bishop of Iria Flavia and Santiago de Compostela in Spain who succeeded Vistruarius.[1]
Cresconius was a supporter of King Ferdinand I of Castile and educated Ferdinand's son, García II of Galicia and Portugal, who would later be crowned by Cresconius himself as king of the newly reestablished Kingdom of Galicia.
Like his contemporary Odo of Bayeux, Cresconius was a "warrior bishop" and during a Viking invasion of Galicia, he gathered an army and defeated the invaders. He fortified Castellum Honesti ‒ a castle known today as Torres do Oeste which once stood in Catoira, Spain ‒ with the goal of blocking future invasions via the estuary, Ría de Arousa, and also built the city walls of Santiago de Compostela.