In 1533, he was involved in a conspiracy against the King. The conspiracy failed, and John VII had to flee to Tallinn. He later returned to Germany and became the chief military commander of Lübeck.
During the Count"s Feud, he fought in Denmark against Christopher of Oldenburg.
He attempted to occupy the island of Funen, however, his army was trounced at Mount Ochsenberg, near Assens, by a Danish army led by Johann Rantzau. John VII fell in that battle, as did many other noblemen, among them Nicholas of Tecklenburg, the Burgrave of Dohna, and Gustav Trolle, the Bishop of Uppsala.