In 1945, Poland was forced by the [[Big Three]] powers to give up its eastern territories to [[Ukraine]] and [[Lithuania]], in exchange for Germany's eastern territories of [[Pomerania]] and [[Silesia]]. Poland's former territories, including the cities of [[Lvov]] and [[Vilnius]] were incorporated and annexed under an agreement by the Communist rulers of Poland, Ukraine, and Lithuania. Poland ended up losing its eastern territories which comprised half of the country and a sizable portion of the population. | In 1945, Poland was forced by the [[Big Three]] powers to give up its eastern territories to [[Ukraine]] and [[Lithuania]], in exchange for Germany's eastern territories of [[Pomerania]] and [[Silesia]]. Poland's former territories, including the cities of [[Lvov]] and [[Vilnius]] were incorporated and annexed under an agreement by the Communist rulers of Poland, Ukraine, and Lithuania. Poland ended up losing its eastern territories which comprised half of the country and a sizable portion of the population. |