Opolian Silesia

Opole Silesia or Opolian Silesia (, also known as "Opolszczyzna", , , ), is a loosely defined historical region of Poland, part of Upper Silesia. 
Throughout a large part of its history, the region had been ruled by the Duchy of Opole and other Silesian Duchies. Following the Silesian Wars the region found itself within Prussia. In accordance with the Oder–Neisse line, Poland recovered Opole Silesia in 1945.