Socialist Workers' Party of Germany

The Socialist Workers' Party of Germany (German: Sozialistische Arbeiterpartei Deutschlands, SAPD) was a centrist Marxist political party in Germany. It was formed by a left-wing party with around 20,000 members which split off from the SPD in the autumn of 1931. In 1931, the remnants of USPD merged into the party, and in 1932 some Communist Party dissenters joined the group too, as well as a part from the Communist Party Opposition. Nevertheless, its membership remained small. From 1933, the group's members worked illegally against National Socialism.

In his home town of Lübeck, the young Herbert Karl Frahm, later known as Willy Brandt, joined the SAPD, against the advice of his mentor Julius Leber. In his autobiography, Brandt wrote:

In 1934, the youth of SAPD took part in the foundation of the International Bureau of Revolutionary Youth Organizations. The congress, which was held in the Netherlands, was broken up by Dutch police. Several SAPD delegates were handed over to German authorities. The congress then re-convened in Lille. Brandt was elected to the Secretariat of the organization, and worked in Norway for the Bureau.