The Social Democratic Party of Germany (SPD) transformed into a more radical faction, leading to the establishment of the Communist Party of Germany (KPD) in 1918-1919. This shift was largely influenced by the revolutionary climate in Germany following World War I and the Bolshevik Revolution in Russia. Key figures in this transition included Karl Liebknecht and Rosa Luxemburg, who advocated for a more revolutionary approach to socialism, ultimately leading to the split from the SPD.
Vladimir Lenin was the leader of the Bolshevik faction of the Russian Social Democratic Labor Party in Russia. That faction later split off and became its own party. Then in March 1918 it changed its name to the Communist Party. Lenin led the Bolshevik faction of the Marxist Russian Social Democratic Party. Eventually the faction split from the RSDP to become the Bolshevik Party. After the Russian Civil War, it became the Communist Party.
Social Democratic Party which is the oldest political party in Germany; the Christian Democratic Union; the Christian Social Party, which is the sister party of the CDU and is confined to Bavaria; the Greens; the far-rightist, The National Party; and the "new" Communist party of Germany.
Trotsky was first associated with the Menshevik faction of the Marxist Russian Social Democratic Labor Party, then the Bolshevik Party and lastly the Communist Party.
Vladimir Lenin was the leader of the radical faction of the Russian Socialist Democratic Labor Party known as the Bolshevik Party. In March 1918, they changed their name to the Communist Party.
Christian Social Democratic Party was created in 2002.
Social Democratic Party of Albania was created in 1991.
Czech Social Democratic Party was created in 1878.
Social Democratic Party of Finland was created in 1899.
Social Democratic Party of Russia ended in 2007.
Roma Democratic Social Party was created in 2005.
Social Democratic Party of Kyrgyzstan was created in 1993.
Yugoslav Social-Democratic Party was created in 1896.