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 no mention of Mieszko's influence on Polish politics. Mieszko died on 28 January 1065. Year of death was noted by "Rocznik kapituły krakowskiej", while day by "Necrologium monasterii superioris Ratisbonensis". He died unmarried and childless. Mieszko Kazimierzowic Mieszko Kazimierzowic ("Kazimierzowic" means "son of Kazimierz") (16 April 1045 – 28 January 1065) was a Polish prince member of the House of Piast. According to some scholars, he was probably Duke of Kuyavia since 1058 until his death. He was the third son of Casimir I the Restorer by his wife Maria Dobroniega, daughter of Vladimir the Great, Grand Duke of Kiev.