Swietopelk I, sometimes called "Swietopelk of Nakło" to distinguish him from other rulers of the same name, was one of the first known Dukes of Pomerania; in the years 1109/13 to 1121 he ruled over Pomerelia. He is usually thought to have been the son of Świętobór I, although other historians make him a brother of Świętobór and son of Siemomysl I. He is mentioned in the chronicle of Gallus Anonymus. The 16th century Pomeranian chronicler Thomas Kantzow also states that Swietopelk was one of the younger sons of Swietibor, who ruled Eastern Pomerania after his father was deposed. The Prussian historianLudwig Giesebrecht, who gave approximate dates for the duke's birth and death, considered him the originator of the Pomeralian dynasty and stated that Swietopelk and his father Swietibor were related to the Piast dynasty through marriage. Other historians have also hypothesized that Swietopelk and Swietibor were related, by blood or by marriage, to the Polish Piast dynasty, or that they served as voyevodas for them in Gdańsk. However, Edward Rymar contests the thesis that Swietopelk was Swantibor's son based on the fact that Gallus Anonymous would have surely mentioned that fact, but rather the chronicler described Swietopelk as a "certain Pomeranian" who was granted control over Polish land by the Polish ruler. Along with his father he was most likely expelled from Pomerania around 1106 by rivals. After Bolesław III Krzywousty defeated Pomeranian dukes at the Battle of Nakło, he gave Swietopelk Nakło, and other grods on the riverNoteć as a fief. After Swietopelk tried to carry out foreign policy without approval of the Polish ruler in 1112, Krzywousty invaded his lands. After a three-month siege of Nakło, he forced Swietopelk to submit. Swietopelk had to pay a tribute to the Polish duke and gave his son as a hostage. In 1113 Swietopelk once again rebelled against Polish rule and Bolesław once again invaded, taking Wyszogród and Nakło. Little is known of his later life. In 1119 Krzywousty defeated two unnamed Pomeranian dukes, taking one prisoner and banishing the other. It is possible that one of them was Swietopelk. According to later chronicles of Jan Długosz and Kantzow, in 1121, a Duke "Odrzanski" named Swietopelk died. Some historians have interpreted this to have been the same Swietopolk, son of Świętobór. However, others consider the "Odrzanski" Swietopolk to have been a different person, Duke of the Chyżans, whose lands were invaded in 1121 by the Saxon prince Lothar of Supplinburg. Swietopelk had several sons, one of whom served as a hostage at the court of Bolesław Krzywousty. It is possible that this unnamed son was the father ofSobieslaw I, Duke of Pomerania, founder of the Samborides dynasty.
