The Silesian tribes (Polish: plemiona śląskie) is a term used to refer to tribes, or groups of West Slavs[1] that lived in the territories of Silesia in the Early Middle Ages. The territory they lived on became part of Great Moravia in 875 (now mostly in the Czech Republic) and later, in 990, the first Polish state created by duke Mieszko I and then expanded by king Boleslaw I at the beginning of the 11th century. They are usually treated as part of the Polish tribes[2] and sometimes as part of the Germanic tribes.[3] Two tribes among them are sometimes considered as Czech (Moravian) tribes.[4]
^Jerzy Strzelczyk [in:] The New Cambridge Medieval History, Cambridge University Press, 1999, p. 521-522 ISBN0-521-36447-7Google Books; Robert Machray, The Problem of Upper Silesia, G. Allen & Unwin ltd. 1945, p. 13 Google Books; Paul Wagret, Helga S. B. Harrison, Poland, Nagel, 1964, p. 231. Google Books