Possibly a Frank by birth, Rupert was bishop of Worms, in Germany, until the end of the seventh century when he began missionary work at Regensburg. He was a successful evangelist in Bavaria, and from there extended his ministry along the Danube River. He was based at Salzburg, in Austria, where he built the first church, monastery and nunnery. One tradition also claimed he had established the salt mines of Salzburg, which he found as the ruins of the Roman town Juvavum. Rupert is seen as one example of the devoted monastic bishop who evangelized the Germans.