Christian Georgiyevich Rakovsky was a Bulgarian-born socialist revolutionary, a Bolshevik politician and Soviet diplomat and statesman; he was also noted as a journalist, physician, and essayist. Rakovsky's political career took him throughout the Balkans and into France and Imperial Russia; for part of his life, he was also a Romanian citizen.

Lev Davidovich Bronstein, better known as Leon Trotsky, was a Russian revolutionary, Soviet politician, journalist, and political theorist. He was a central figure in the 1905 Revolution, October Revolution, Russian Civil War, and the establishment of the Soviet Union. Alongside Vladimir Lenin, Trotsky was widely considered the most prominent Soviet figure and was de facto second-in-command during the early years of the Russian Soviet Republic. Ideologically a Marxist and a Leninist, his thought and writings inspired a school of Marxism known as Trotskyism.