East Upper Silesia (German: Ostoberschlesien) is the easternmost extremity of Silesia, the eastern part of the Upper Silesian region around the city of Katowice (German: Kattowitz).[1] The term is used primarily to denote those areas that became part of the Second Polish Republic on 20 June 1922, as a consequence of the post-World War I Treaty of Versailles. Prior to World War II, the Second Polish Republic administered the area as Autonomous Silesian Voivodeship.