Mieszko I of Poland elders, and limited their authority. Clergy who arrived in the country contributed to the development of education and culture, and of the state administration and diplomacy, as well. At the end of Mieszko's reign (ca. 990), Poland began to pay tribute to the pope (Peter's Pence). However, the conversion of the Polish population to Catholicism was a long-term process, and was not completed during the reign of Mieszko I. The duke probably had to deal with rebellions led by the old pagan priest caste. In some villages, the old Slavic beliefs and customs were continued until the 16th century. After
Mieszko I Tanglefoot Casimir II's eldest son, Leszek the White. Both sides clashed in the bloody Battle of Mozgawa (Mozgawą) near Jędrzejów (13 September 1195), where Mieszko III was seriously injured and his son Bolesław of Kuyavia died. The Silesian troops, led by Mieszko and Jarosław, arrived to the battlefield too late, soon after Mieszko III withdrew to Kalisz. Despite the forces of the Count palatine Goworek who also arrived to help Leszek's troops, the Silesians obtained a great victory; however, because Mieszko III wasn't present, this victory brought to them only benefits in terms of prestige (not counting the ransoms obtained by