Stanisław of Masovia
Polish prince / From Wikipedia, the free encyclopedia
Stanisław of Masovia (pl: Stanisław mazowiecki; 17 May 1501[1] – 8 August 1524), was a Polish prince member of the House of Piast in the Masovian branch. He was a Duke of Czersk, Warsaw, Liw, Zakroczym and Nur during 1503-1524 (under regency until 1518) jointly with his brother.
He was the eldest son of Konrad III the Red and his third wife Anna, a daughter of Mikolaj Radziwiłł the Old, Voivod of Vilnius and the first Grand Chancellor of Lithuania.