"Polish tribes" is a term used sometimes to describe the tribes of West Slavic Lechites that lived from around the mid-6th century in the territories that became Polish with the creation of the Polish state by the Piast dynasty. The territory on which they lived became a part of the first Polish state created by duke Mieszko I and expanded at the end of the 10th century, enlarged further by conquests of king Bolesław I at the beginning of the 11th century.
In about 850 AD a list of peoples was written down by the Bavarian Geographer. Absent on the list are Lechitic-speaking Polans, Pomeranians and Masovians, who became known later and were written about by Nestor the Chronicler in his Primary Chronicle (11th/12th century).
The most important tribes who were conquered by Polans were the Masovians, Vistulans, Silesians and Pomeranians.[1] These five tribes "shared fundamentally common culture and language and were considerably more closely related to one another than were the Germanic tribes."[2]