Bolesław III had his half-brother blinded, then split Poland among his sons in 1138, and the country stayed divided for about two centuries

Bolesław III Krzywousty was born on 20 August 1086, son of Duke Władysław Herman. After his father died in 1102, he fought his half-brother Zbigniew for the country. After peace with Germany and Bohemia in 1111, Bolesław had Zbigniew blinded. The historian Bożena Czwojdrak says a very hot rod was held close to the eyes. Zbigniew probably died in 1113 at the Benedictine abbey of Tyniec. The blinding caused public outrage, and Bolesław did public penance in a hair shirt. In 1138 he issued a succession statute to stop his own sons fighting. Władysław II received Silesia, Bolesław IV Masovia and Kuyavia, Mieszko III Greater Poland, and Henryk the Sandomierz land. The youngest, Kazimierz, was born after his father's death and got nothing. A fifth territory, centred on Kraków, could not be divided or inherited. It went to the eldest Piast, the senior, who held authority over the others. Bolesław died on 28 October 1138 and was buried in Płock cathedral. Within three years the brothers were at war. In 1146 the juniors drove the senior, Władysław II, out of Poland. No original text of the statute survives. Polish school history ends the period of division with Władysław I Łokietek's coronation in Kraków in 1320.