Mieszko I of Poland before his death among a number of princes. They were probably his sons: Bolesław I the Brave, Mieszko and Lambert. In 1999 the archeologist Hanna Kóčka-Krenz located what's left of Mieszko's palace-chapel complex in Poznań. The basic structure of the early Polish state was Mieszko's military force. The ruler managed to create an army composed of about 3,000 mounted warriors. This increasingly powerful force allowed the Polans to attack weaker neighboring tribes and conquer their lands. A key factor promoting cohesion of the growing state was fear of the invaders impressed by them among local populations. The first Piasts reinforced
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