The Second World War ended in defeat for Germany in May 1945 , and with that ended the twelve Nazi years and a national policy driven by anti-Semitism . It also seemed reasonable to assume that the end of the Hitler regime meant an end to one-party dictatorship . The entire central part of what had been Germany , including Leipzig and Castle Thallwitz , now became designated as the Soviet occupation zone : this was part of a larger scheme of border changes and other territorial provisions agreed by the political leaders of the victorious powers at the Yalta Conference . Rosenthal joined the Social Democratic Party ( SPD ) in 1945
Yalta Conference
Yalta Conference
Wolfgang Rosenthal