 What became East Germany was traditionally the heartland for the SPD in united Germany.In 1946, the Soviet occupation authorities forced the eastern branch of the SPD to merge with the eastern branch of the Communist Party of Germany to form the Socialist Unity Party of Germany (SED).Within a short time, however, the few independent-minded members from the SPD side of the merger had been pushed out, and the SED became a full-fledged Communist party–essentially the KPD under a new name.