Bamberg is a town in Bavaria, Germany, located in Upper Franconia on the river Regnitz close to its confluence with the river Main. Its historic city center is a listed UNESCO world heritage site. During the post-Roman centuries of Germanic migration and settlement, the region afterwards included in the Diocese of Bamberg was inhabited for the most part by Slavs. The town, first mentioned in 902, grew up by the castle Babenberch which gave its name to the Babenberg family. On their extinction it passed to the Saxon house. The area was Christianized chiefly by the monks of the Benedictine Fulda Abbey, and the land was under the spiritual authority of the Diocese of Würzburg. In 1007, Holy Roman Emperor Henry II made Bamberg a family inheritance, the seat of a separate diocese. The emperor's purpose in this was to make the Diocese of Würzburg less unwieldy in size and to give Christianity a firmer footing in the districts of Franconia, east of Bamberg.