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 of Poland been between 922–945; the activity of the Duke in his final years of life puts the date of his birth closer to the latter year. There are three major theories concerning the origin and meaning of Mieszko I's name. The most popular theory, proposed by Jan Długosz, explains that Mieszko is a diminutive of "Mieczysław", a combination of two elements or lexemes: "Miecz" meaning sword and "Sław" meaning famous. Today, this theory is rejected by the majority of Polish historians, who consider the name Mieczysław to have been invented by Długosz to explain the origin of the name Mieszko. Today,