in east germany, the soviet occupation authorities forced the eastern branch of the spd to merge with the kpd (led by pieck and ulbricht) to form the socialist unity party (sed) in april 1946. although nominally a union of equals, the sed quickly fell under communist domination, and most of the more recalcitrant members from the spd side of the merger were pushed out in short order. by the time of the formal formation of the east german state in 1949, the sed was a full-fledged communist party, and developed along lines similar to other soviet-bloc communist parties. it was the ruling party in east germany from its formation in 1949 until 1989. the spd managed to preserve its independence in berlin, forcing the sed to form a small branch in west berlin, the socialist unity party of west berlin.