[1] In 1434, around the age of eight, following the death of his father, Casimir V, duke Joachim succeeded him as a ruler of the Duchy of Pomerania-Stettin.

Frederick II, Prince-elector of the Margraviate of Brandenburg, intervened in the negotiations, demanding Pomerania-Stettin to cede the conquered territory of Uckermark to him, including Pasewalk, and Torgelow.

It caused numerous protests of the law by trading guilds, including the city of Stargard.

[4][5] Frederick II finally renounced his claims towards Pomerania, following the promise of obtaining the towns after the extinction of the entire male line of the House of Griffin.

[1] Due to him being underage, the state probably was under the regency of duke Wartislaw IX, and Otto's mother, Elisabeth, who remained under the influence of Frederick II.