In the summer of 1944, the advancing Red Army, assisted by the Polish Home Army forces (locally implementing Operation Tempest), pushed the Wehrmacht out of Lviv. and the university reopened. Due to post-war border changes, the Polish population of the city was expelled and most of Polish academics from the University of Jan Kazimierz relocated to Wrocław (former Breslau), where they took up positions in the newly established Polish institutions of higher learning. The buildings of the university had survived the war undestroyed, however, 80% of its pre-war student and academic body was gone. The traditions of Jan Kazimierz University have been duplicated at the University of Wrocław, which replaced the pre-war University of Breslau after the German inhabitants of that city had been expelled following Stalin's establishing Germany's eastern border farther to the west.