The Count became one of Sigismund's most powerful advisers, and it was easy for him to obtain the bishopric of Freising for his son Hermann when it suddenly fell vacant.
At this time Hermann was studying in Bologna, when on 26 July 1412 Pope John XXII, on the intervention of the German emperor Sigismund, named him Bishop of Freising.
In the summer of 1419 he agreed an alliance with the bishops of the ecclesiastical province of Salzburg, under the leadership of the Archbishop, for the protection of their spiritual Immunitätsrechte with the promise of mutual support against the territorial princes.
[3] Because of their good relations with the king the family was able to persuade Pope Martin V to transfer him to the seat of the Prince-Bishop of Trent, vacant since the banishment of George of Lichtenstein in August 1419.
The Papal nomination took place on 29 March 1421, but Martin V was oblige to rescind it on 13 September 1421, as the cathedral chapter of Trent were not willing to accept Hermann, because of his severe hernia.