Duchy of Poland.

About Duchy of Poland

The period of rule by the Piast dynasty between the 10th and 14th centuries is the first major stage of the history of the Polish state. The dynasty was founded by a series of dukes listed by the chronicler Gall Anonymous in the early 12th century: Siemowit, Lestek and Siemomysł. It was Mieszko I, the son of Siemomysł, who is considered the founder of the Polish state. Mieszko converted to Christianity of the Western Latin Church in an event known as the Baptism of Poland in 966. His acceptance of Christianity marked the formal beginning of Polish statehood, which was recognized by the Papacy and other Christian states of Europe. The Papal incipit titled Dagome iudex, first defined Poland's geographical boundaries and affirmed that Mieszko was under the protection of the Apostolic See. Mieszko also completed a unification of the Lechitic tribal lands that was fundamental to the existence of the new country of Poland. The ruling house then remained in power in the Polish lands until 1370.