Georgi Plekhanov, Russian philosopher and theorist (b. 1856)
Georgi Valentinovich Plekhanov (; Russian: Гео́ргий Валенти́нович Плеха́нов, IPA: [ɡʲɪˈorɡʲɪj vəlʲɪnˈtʲinəvʲɪtɕ plʲɪˈxanəf] (listen); 11 December [O.S. 29 November] 1856 – 30 May 1918) was a Russian revolutionary, philosopher and Marxist theoretician. He was a founder of the social-democratic movement in Russia and was one of the first Russians to identify himself as "Marxist". Facing political persecution, Plekhanov emigrated to Switzerland in 1880, where he continued in his political activity attempting to overthrow the Tsarist regime in Russia. Plekhanov is known as the "father of Russian Marxism".

Born to a Tatar noble family of serf-owning landlords and minor government officials, Plekhanov grew up to reject his social class. As a student he became a Marxist. Although he supported the Bolshevik faction at the 2nd Congress of the Russian Social Democratic Labour Party in 1903, Plekhanov soon rejected the idea of democratic centralism, and became one of Vladimir Lenin and Leon Trotsky's principal antagonists in the 1905 St. Petersburg Soviet.

During World War I, Plekhanov rallied to the cause of the Entente powers against Germany and he returned home to Russia following the 1917 February Revolution. Plekhanov was an opponent of the Bolshevik state which came to power in the autumn of 1917. He died the following year. Despite his vigorous and outspoken opposition to Lenin's political party in 1917, Plekhanov was held in high esteem by the Communist Party of the Soviet Union following his death as a founding father of Russian Marxism and a philosophical thinker.