As a youthful knight, he often engaged in combat with the Lithuanians, and according to monastic legend, defeated the Grand Duke of Lithuania, Vytenis, in a duel.

In 1339, a dispute between him and then grandmaster Dietrich von Altenburg resulted in Dusemer's demotion and exile to Brodnica, where he became commander.

The Teutons intended to subdue the entirety of Lithuania, however, the Black Death reached Prussia in that year, resulting in Dusemer being forced to widthraw his troops from the area.

In 1349 he approved one of the rare monastery foundations of the time of the order for the Benedictine nuns in Löbenicht .

Talks with the Kingdom of Poland resulted in the establishment of a definitive Teutonic-Polish border in 1349 in Pomerania.