Leszek I the White

Leszek the White (; c. 1184/85 – 24 November 1227) was Prince of Sandomierz and High Duke of Poland in the years 1194–1198, 1199, 1206–1210, and 1211–1227. During the early stages of his reign, his uncle Duke Mieszko III the Old and cousin Władysław III Spindleshanks, from the Greater Polish branch of the royal Piast dynasty, contested Leszek's right to be High Duke.

Leszek was the third or fourth, but eldest surviving son of Casimir II the Just and his wife Helen of Znojmo. Provided by Wikipedia