In 1945 , with the approaching Red Army a significant number of residents were either evacuated or fled the city at their own discretion . Following the Yalta Conference , Gliwice , along most of Silesia , was incorporated into communist Poland , and the remaining German population was expelled . Ethnic Poles , themselves expelled from the Polish Kresy ( which were incorporated into Soviet Union ) , started to settle down in Gliwice . Population estimates reached their pre-war levels in 1950 , at 119,968 people . Gliwice 's population peaked in 1988 at 223,403 inhabitants
Yalta Conference
Yalta Conference
Gliwice