The first Apostle of Christianity for the territory now included in the Diocese of Würzburg was the Irish missionary, Saint Kilian, the Apostle of Franconia. who converted Gozbert the Frankish duke of Thuringia.[1] In his castle above Würzburg, Gozbert's son Hedan II built the first church dedicated to the Blessed Virgin; on this account the castle received the name of Marienberg.[2] The first mention of Würzburg is in 704, when it is called Castellum Virtebuch.[3] A diocese was established in Würzburg by Saint Boniface, who in 741 consecrated his friend Saint Burchard as bishop;[4] In 742 Pope Zachary confirmed the selection of Burchard. Burchard (741-53) built the first cathedral church, and buried there the bodies of St. Kilian and his companions; he connected with the church a monastery which followed the Rule of St. Benedict. [5]
Carloman (mayor of the palace) gave great gifts of land to the bishopric. In 752 or 753 the church of Würzburg was granted immunity for all its possessions, also secular jurisdiction, whereby the foundation was laid for the future secular authority of the bishops. Like the majority of his successors, Burchard lived at the Marienburg, which he had received from the last duke in exchange for another fortified castle. His successor, Megingoz (753-85), did much towards Christianizing Saxony.[6] Bishop Bernwelf (785-800) replaced the Benedictine secular clergy at the cathedral by the Brothers of St. Kilian, who led a common life after the rule of Chrodegang of Metz. Arno (855-92) rebuilt the cathedral, which had been destroyed by lightning, on the site of the present cathedral.
^ abPalmer, James. "The 'Vigorous Rule' of Bishop Lull: Between Bonifatian Mission and Carolingian Church Control". Early Medieval Europe. 2005, 13 (3): 249–76. doi:10.1111/j.1468-0254.2005.00158.x