He was a contemporary of Childebert III, King of the Franks, and is a Saint in the Roman Catholic and an Eastern Orthodox Churches. Rupert is also a patron saint of the Austrian state of Salzburg. Holy tradition states that Rupert was a scion of the Frankish royal Merovingian family, related to the Robertian dynasty.
But, his fortune changed soon after when Duke Theodo of Bavaria requested that he come to Bavaria to help spread the Catholic faith in the region.
Rupert then moved to Altötting where he converted the local people. He sailed down the Danube river, visiting many towns, villages, and forts.
Soon he had converted a large area along the Danube southward to the border with the Pannonian lands which were ruled by the Avars. Here he stayed at Lorch (the former Roman city of Lauriacum, today part of Enns).
The dangerous and warlike conditions, however, made him abandon plans of missionary work in the Avar territories.
Instead he proceeded to the then ruined Roman city of Juvavum where he made his base and renamed the city "Salzburg" (Latin: Salisburgum). Rupert was able to build on ancient Early Christian traditions that were already in practice. He re-established Saint Peter"s Abbey and laid the foundations of Salzburg Cathedral which was eventually finished by his successor Vergilius.
Along with converting the locals, Rupert introduced education and other reforms.
From the hands of Duke Theodo of Bavaria, he received further estates around Piding and Reichenhall, where he promoted the development of the local saltworks. Rupert reportedly died on Easter Sunday around 710.
According to other sources, he returned to his hometown of Worms where he died in 717. His remains were transferred to Salzburg Cathedral by 774.
In Austria, it is on the 24th of September.