On his appointment, John of Carlowitz, a relative of his predecessor began a feud over the inheritance of the episcopal estate.
The so-called Pig War or Saukrieg lasted 3 years before it was resolved by Elector Augustus.
In 1559, he appointed Johann Leisentrit as the Administrator of the remaining Roman Catholic areas.
After John's death, she married the Electoral Saxon Advisor (Rat) and Amtmann of Stolpen, Hans Georg von Wehse, and had four daughters from that marriage.
John IX died in Mügeln on 26 March 1595; his gravestone is in the town church of Neu-Mügeln.