How was the Social Democratic Party of Germany absorbed into East Germany’s Socialist Unity Party in 1946?

In April 1946, under pressure from Soviet occupation authorities, the leadership of the Social Democratic Party (SPD) in the Soviet zone agreed to merge with the Communist Party (KPD). This merger resulted in the formation of the Socialist Unity Party (SED).12

While ostensibly presented as a combination of the two parties, the SED was in practice a communist-dominated organization. Following the merger, the party increasingly fell under strict communist control, and Social Democrats were systematically purged from its leadership ranks. By forcing other parties into a permanent coalition under its leadership, the SED effectively avoided free, competitive elections and established itself as the ruling power in East Germany. This forced unification was denounced by Social Democrats in the Western zones, who maintained their independence.21