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 the Sandomierz nobles captured in the battle). On 22 March 1201 Jarosław of Opole died. The Duchy of Opole was then inherited by his father Bolesław the Tall, with whom the late Duke was recently reconciled. Bolesław the Tall died only nine months later, on 7/8 December 1201, leaving all his lands to his eldest (and only) surviving son Henry I the Bearded. Mieszko was determined to obtain Opole and made a surprise attack at the beginning of 1202. The Duke managed to obtain Opole, which was from then on definitely joined to his lands. Despite this victory, Mieszko wanted