Rosa Luxemburg (1871-1919) was a Polish-born Jewish revolutionary and one of the greatest theoretical minds of the European socialist movement. An activist in Germany and Poland, the author of numerous classic works, she participated in the founding of the German Communist Party and the Spartacist insurrection in Berlin in 1919. She was assassinated in January of that year and has become a hero of socialist, communist and feminist movements around the world.

Karl Marx was born in the German city of Trier in 1818. He studied law in Bonn and Berlin at his father's insistence, but his true interests lay elsewhere and, in 1841, he received a doctorate in philosophy from the University of Jena.

For the next two years he wrote for radical left-wing newspapers before moving to Paris with his wife, Jenny; there he became a communist and met his lifelong friend and collaborator, Friedrich Engels.

They published their revolutionary pamphlet, The Communist Manifesto, in 1848 and Marx moved to London a year later. He spent the rest of his life there - often in considerable poverty - while he wrote his magnum opus of political theory, Das Kapital. Karl Marx died in 1883.

Ernesto Guevara De La Serna was born in Rosario, Argentina, on June 14, 1928. While studying for a medical degree in Buenos Aires, he took a trip with his friend Alberto Granado on an old Norton motorcycle through all of Latin America, the basis for The Motorcycle Diaries. During his travels he witnessed the Bolivian revolution in 1953; and, in Guatemala in 1954, the overthrow of the democratically elected government of Jacobo Arbenz by US-backed forces.

Forced to leave Guatemala, he went to Mexico City, where he linked up with exiled Cuban revolutionaries and met Fidel Castro in 1955. Che joined their expedition to Cuba, where the revolutionary war began in the Sierra Maestra mountains. At first Che was the troop doctor, and later became Rebel Army commander in July 1957. Following the rebels' victory on January 1, 1959, he was a key leader of the new revolutionary government and also of the political organization that in 1965 became the Communist Party of Cuba.