History of Poland
The Polish People's Republic ("Polska Rzeczpospolita Ludowa") was established under the rule of the communist Polish United Workers' Party (PZPR). The name change from the Polish Republic was not officially adopted, however, until the proclamation of the Constitution of the Polish People's Republic in 1952.
Formation of the Eastern Bloc
Fraudulent Polish elections held in January 1947 resulted in Poland's official transformation to a non-democratic Communist state by 1949, the People's Republic of Poland. Resistance fighters continued to battle Soviet forces in the Ukrainian annexed portions of eastern Poland, the Soviet response to which included the arrest of as many as 600,000 people between 1944 and 1952, with about one third executed and the rest imprisoned or exiled.