Cresconius (Spanish: Cresconio) (c. 1036 – 1066) was a bishop of Iria Flavia and Santiago de Compostela during the eleventh century. He succeeded Vistruarius (Vistruario).[1]
He was a supporter of Ferdinand I of Castile and educated this king's son. Ferdinand's son, García II of Galicia and Portugal, was later crowned by Cresconius himself as king of Galicia.
Like his contemporary Odo of Bayeux, Cresconius was a "warrior bishop." During a Viking invasion of Galicia, Cresconius gathered an army and, assuming leadership of the Galician nobility, defeated the invader.
He fortified the site known as Castellum Honesti, today Torres del Oeste near Padrón, with the goal of blocking future invasions via the Arosa. He built the city walls of Santiago de Compostela and enlarged his diocese.
Cresconius believed that, because Santiago was the burial place of Saint James the Greater, that his see naturally occupied a superior place amongst the dioceses of the West as an "apostolic see." To this end, he proclaimed himself Episcopus Iriensis et Apostolicae Sedis. However, this assumption was not supported by Rome and Pope Leo IX excommunicated him at the Council of Rheims (1049). Nevertheless, Cresconius continued using this title, and the bishops of Lugo, Dumio, Oviedo, and Oporto acknowledged his authority and primacy.
In 1060, he presided over the Council of Compostela where he prohibited the use of weapons by clerics, and also forbade that clerics be married. He opened parochial schools and fought pagan superstitions that dated to even before the Roman conquest of Galicia.