Swantibor I, previously referred to by historians as Swantibor III ( – 21 June 1413) was a member of the House of Griffins, a Duke of Pomerania-Stettin and for a while governor of the Mittelmark. Life Duke Swantibor I was a son of Barnim III, nicknamed the church founder (born: ; died: 1368), who ruled in the Teilherzogtum of Pomerania-Stettin. After Barnim III's death in 1368, his three surviving sons Casimir III, Swantibor I and Bogislaw VII ruled Pomerania-Stettin jointly. At the time of their succession to power, Denmark under King Waldemar IV of Denmark was at war with the Hanseatic League and its allies, in particular Duke Albert II of Mecklenburg. The late Duke Barnim III had sided with Denmark. His sons, however, made peace with Albert on 7 November 1368 and took a neutral stance towards Denmark. This brought them into conflict with Margrave Otto of Brandenburg, who sided with Denmark. This conflict escalated to war. Duke Casimir III died during the siege of Chojna in 1372. After Casimir's death, Swantibor I and Bogislaw VII ruled jointly, with Swantibor I now playing the leading role. He was faced with the challenge to maintain the position of Pomerania, which was splintered into several Teilherzogtumer, against its neighbours, in particular, against Brandenburg. When Emperor Charles IV (1316–1378) tried to win Brandenburg for his relatives, Swantibor initially feared that Charles IV would revive old claims that Brandenburg held suzerainty over Pomerania. On 17 May 1373 all the Pomeranian dukes, that is, Swantibor I and Bogislaw VII from Pomerania-Stettin, Wartislaw VI and Bogislaw VI from Pomerania-Wolgast, Bogislaw V of Pomerania-Stolp and Philip of Rehberg, Bishop of Cammin, joined forces to protect their interests and their common ownership of Pomerania. When Emperor Charles IV had acquired Brandenburg for his family by the Treaty of Fürstenwalde of 15 August 1373, however, Charles initiated a friendly relation with the Pomeranian dukes, contrary to their expectations, perhaps because he had married Bogislaw V's daughter, Elisabeth of Pomerania. Charles IV was particularly friendly with Swantibor, who occasionally participated in imperial affairs, and who served as an imperial judge. The situation in Pomerania remained disorganized. The Dukes had conflicts with the Pomeranian cities and were short of funds due to their ongoing feuds. The relation with the neighbouring Teutonic Knights was inconsistent. In 1388, Swantibor I and Bogislaw VII served the order for a while. In 1403, however,