Mestwin I[1][2] (Polish: Mściwoj I gdański or Mszczuj I, Kashubian: Mscëwòj I; c. 1160 – 1/2 May 1219 or 1220) was Prince of Pomerelia (styled himself as princeps Pomoranorum)[3] from about 1205 until his death.
Mestwin was a member of the Samborides dynasty, the son of Duke Sobiesław of Gdańsk and younger brother of Sambor I, whom he succeeded in Pomerelia. In the tables of Oliwa Abbey, outside Gdańsk, he is recorded as pacificus ("the Peaceful").
^On a recently-discovered Seal-stamp of Duke Mestwin I., of East Pomerania," by H. Ernst Strehlke. - The Numismatic Chronicle, p. 158, Royal Numismatic Society (Great Britain), 1966 [1]
^Loew PO: Danzig. Biographie einer Stadt, Munich 2011, p. 32: "Sambor [...] styled himself 'princeps Pomoranorum,' [...], but not 'dux,' which was the privilege of the Piasts." p. 33: "After Sambor's death [...] his brother Mestwin [...] strove after gaining ever greater independence from Poland. He confidently styled himself 'princeps in Danzk' and expanded southwards. His oldest son Swantopolk (Swietopelk), ruling from 1217 onwards, exploited Poland's fragmentation to acquire independence for his realm; already since 1227 he styled himself 'dux,' 'Duke of Pomerelia.'"
^Wspomniany Mestwin I ... znamiennym zwrotem nunc princeps in Gdanzk podkreślił, że obecnie już nie w jednym z podrzędnych, ale w naczelnym grodzie się ..., p.59 of Zapiski historyczne, by Towarzystwo Naukowe w Toruniu, Wydział Nauk Historycznych [2]
^Urban, William (2000). The Prussian Crusade (2nd ed.). Chicago, Illinois: Lithuanian Research and Studies Center. p. 185. ISBN0-929700-28-7.