From 610 to 612 Saint Columbanus and Saint Gall worked as missionaries in Bregenz. From 917 onwards the castle served as a residence of the Udalrichinger (ruling dynasty of Vorarlberg), who called themselves Counts of Bregenz. The house died out around 1150. The son of the first Ulrich was Saint Gebhard, born in 947. He became the Bishop of Konstanz. In around 1170 Hugo of Tübingen (Montfort) founded a town settlement (first documented in 1249), enlarged it in the 13th and 14th centuries and from 1650 to 1652.