He was one of the younger sons of Margrave Leopold III, the Holy. Through his mother Agnes, he was related to the Hohenstaufen. In the course of their struggle against the competing Welfen family, he was given the formerly Welfish Bavaria as a fief by Emperor Conrad III. The most important measure of his short reign was the Exchange of Mautern entered into with the Bishop of Passau in 1137.
The bishop was given the Saint Peter"s Church in Vienna, while the Margrave received extended stretches of land from the bishop outside the city walls, with the notable exception of the territory where a new church was to be built, which was to become Saint Stephen"s Cathedral.