History of Poland during the Piast dynasty
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.
Source: Wikipedia — History of Poland during the Piast dynasty (CC BY-SA 4.0)