Siemowit I of Masovia

Siemowit I
Siemowit I, Duke of Masovia by Jan Matejko
Duke of Masovia
Reign1248–1262
PredecessorBolesław I of Masovia
SuccessorKonrad II of Masovia
Died23 June 1262
SpousePereyaslava of Halych
IssueKonrad II of Masovia
Bolesław II of Masovia
Salomea
HouseHouse of Piast
FatherKonrad I of Masovia
MotherAgafia of Rus

Siemowit I of Masovia (Polish: Siemowit (Ziemowit) I mazowiecki) (d. 23 June 1262), was a Polish prince member of the House of Piast, Duke of Czersk during 1247–1248, Duke of Masovia (except Dobrzyń) during 1248–1262, ruler over Sieradz during 1259–1260.

He was the sixth son of Konrad I of Masovia and his wife Agafia of Rus.[1]

  1. ^ Rowell 1994, p. xxix.