Mieszko I of Poland husband from the monastery of Kalbe. They had three sons: After a struggle for power between Bolesław I and Oda with her minor sons (Bolesław's half-brothers), the eldest son of Mieszko I took control over all of his father's state and expelled his stepmother and her sons from Poland. Mieszko I of Poland Mieszko I (; – 25 May 992) was the ruler of the Polans from about 960 until his death. A member of the Piast dynasty, he was a son of the legendary Siemomysł, and a grandson of Lestek. He was the father of Bolesław I the Brave
Mieszko Kazimierzowic "Gesta principum Polonorum" written in the early 12th century, put Mieszko third in order, among his brother. Modern historian, Janusz Bieniak, has supposed that Mieszko was the second son of Casimir I and was older than Władysław Herman, but most scholars disagree with this hypothesis. The date of Mieszko's birth was given by "Rocznik krakowski" (Kraków Annals). This source omitted dates of birth of Mieszko's brothers. Kazimierz Jasiński thought that "Rocznik" was started shortly before Mieszko's birth and this was the reason for absence of his older brothers. Przemysław Wiszewski supposed tha Casimir I chose Mieszko as his successor and