Otto II was the eldest son of Duke Swantibor III, of Pomerania-Stettin and his wife Anna of Hohenzollern.
Otto was confirmed as Archbishop in 1394 by King Wenceslaus and in 1396, he went to Dorpat, where he created an alliance with Grand Duke Vytautas of Lithuania.
In the following years, however, the Teutonic Order prevailed and Otto returned to Pomerania and this episode was without lasting results.
Swantibor III retired in 1412 and left government to his two sons Otto II and Casimir V. They fought the inconclusive Battle of Kremmer Damm against Brandenburg on 12 October 1412.
When Duke Swantibor III died on 21 June 1413, Otto II and Casimir V decided to rule Pomerania-Stettin jointly.
According to the historian Martin Wehrmann, there is no evidence for such a marriage and the rumour is probably based on the alliance between Otto and Vytautas.