Fernando Claudín: Spanish writer who joined the Spanish Communist Party in the early thirties and actively participated in the Spanish Revolution. Went into exile after the victory of fascism in Spain in 1939 and remained a prominent member of the Spanish Communist Party until 1964. Expelled from the party for criticizing its rigid stalinism. Wrote a two-part book about the failure of the Comintern and the harm stalinism and stalinist intervention had on the revolutionary movements of the world.
Isaac Deutscher: Polish marxist historian who began his revolutionary life in Warsaw as a member of the Polish Communist Party during its days of illegality under Pilsudski's military dictatorship. In the thirties he became one of the most prominent and principled members of a leftist opposition group within the Polish CP which eventually sided with Trotsky. Expelled from the party in 1931, Deutscher continued his revolutionary work outside the party. In 1939, a few months before the outbreak of WWII, he traveled to Britain as a journalist for a Polish paper, thus inadvertently escaping the Holocaust. In Britain Deutscher focused his energies on historical writing, and produced his famous three part biography of Trotsky and his biography of Stalin as well as many other important and useful books on the Russian revolution and its aftermath. A committed, serious, 'traditional' Marxist to his death, Deutscher remained a fierce critic of Stalinism and of orthodox Troskyism.

Maxim Gorky: Novelist and playwright, he grew up in poverty. In his youth Gorky traveled around Russia on foot and took on many short-term odd jobs to support himself. During and after his wanderings he began writing for provincial newspapers as well as preparing more substantial works. A master of short stories, novels, plays, and articles, his works focused on social questions and he was an open partisan of the downtrodden. Considered to be the founder of Socialist Realism, by the turn of the century he was an open supporter of the Russian Social Democratic Party: he was considered the writer of the Russian Marxists. Gorky was and will remain one of the greatest socialist novelists ever to pick up a pen, with an unrivaled ability in writing about the oppressed: sympathetically, realistically, and with the spirit of revolution.

Jaroslav Hašek: Famous Czech satirist, originally an anarchist involved in anti-militarist campaigns, he was forcibly drafted into the Austro-Hungarian Army and quickly deserted to the Russian Army. After the Russian Revolution he joined the Red Army in 1918 and served heroically until the end of 1920 when he was sent back to Czechoslovakia to help the new Czechoslovak Communist Party. Died two years after he returned to Czechoslovakia, isolated due to his involvement with the Red Army in Russia and the wide repression of the Czechoslovak communists at the end of 1920. Wrote a short collection of humorous sketches about his time in the Red Army during the Civil War, entitled The Bugulma Stories.

Solomon Lozovsky: Russian revolutionary, he joined the Russian Social Democratic Party in 1901 and a long series of arrests and exiles followed. After the split in the party he sided with the Bolsheviks, however he was expelled in 1914 due to his advocacy for reuniting the parties different factions. After returning to Russia from exile and participating in the October Revolution, he was readmitted to the party in 1917. Soon after, however, in 1918, he was newly expelled for his support for independent trade unions and his advocacy for a government open to the left, not just the Bolsheviks. Lozovsky was readmitted in 1919 and from then on ceased criticism of the party's line. From 1920 to 1937 he was the general secretary of the Profintern, the union of communist unions tied to the Comintern. During WWII he had a major role in leading the anti-fascist and anti-racist propaganda. After the war in 1949, Lozovsky was arrested, sentenced to death, and in 1952 executed.

Victor Serge: Child of Russian exiles, he grew up in Belgium and France. After the Russian Revolution he made his way to the Soviet Union in 1919. He held various positions in the new government, including in the Comintern. Sided with Trotsky and the opposition to Stalin and was repeatedly jailed until he was exiled from the Soviet Union in 1936. Remained a principled communist till his death in exile in Mexico in 1947. Wrote many novels on the Russian Revolution in addition to his Memoirs and other books on the history of the Russian Revolution.

Alexander Shlyapnikov: The leader of the Workers Opposition, the first internal opposition group in the Soviet Communist Party. An old Bolshevik, Shlyapnikov was an active and important party member long before the Revolution and an example of a committed communist worker. Before the Revolution Shlyapnikov traveled around Europe organizing the transportation of illegal literature into Russia, raising money for the party, and carrying out other party tasks. After returning secretly to Russia in 1916, Shlyapnikov played a prominent role in the party's Petrograd branch and was one of the few Bolshevik leaders to be present there during the February Revolution. Shlyapnikov was imprisoned in 1935, and refused to declare he was guilty of imaginary crimes. He was subsequently executed in 1937.