Exiled Russian revolutionary Leon Trotsky is fatally wounded by an ice-ax-wielding assassin at his compound outside Mexico City. The killer—Ramón Mercader—was a Spanish communist and probable agent of Soviet leader Joseph Stalin. Trotsky died from his wounds the next day.

Born in the Ukraine of Russian-Jewish parents in 1879, Trotsky embraced Marxism as a teenager and later dropped out of the University of Odessa to help organize the underground South Russian Workers’ Union. In 1898, he was arrested for his revolutionary activities and sent to prison. In 1900, he was exiled to Siberia.

In 1902, he escaped to England using a forged passport under the name of Leon Trotsky (his original name was Lev Davidovich Bronshtein). In London, he collaborated with Bolshevik revolutionary Vladimir Ilyich Lenin but later sided with the Menshevik factions that advocated a democratic approach to socialism. With the outbreak of the Russian Revolution of 1905, Trotsky returned to Russia and was again exiled to Siberia when the revolution collapsed. In 1907, he again escaped.

During the next decade, he was expelled from a series of countries because of his radicalism, living in Switzerland, Paris, Spain and New York City before returning to Russia at the outbreak of the revolution in 1917. Trotsky played a leading role in the Bolsheviks’ seizure of power, conquering most of Petrograd before Lenin’s triumphant return in November. Appointed Lenin’s secretary of foreign affairs, he negotiated with the Germans for an end to Russian involvement in World War I. In 1918, he became war commissioner and set about building up the Red Army, which succeeded in defeating anti-communist opposition in the Russian Civil War. In the early 1920s, Trotsky seemed the heir apparent of Lenin, but he lost out in the struggle of succession after Lenin fell ill in 1922.

In 1924, Lenin died, and Joseph Stalin emerged as leader of the USSR. Against Stalin’s stated policies, Trotsky called for a continuing world revolution that would inevitably result in the dismantling of the increasingly bureaucratic Soviet state. He also criticized the new regime for suppressing democracy in the Communist Party and for failing to develop adequate economic planning. In response, Stalin and his supporters launched a propaganda counterattack against Trotsky. In 1925, he was removed from his post in the war commissariat. One year later, he was expelled from the Politburo and in 1927 from the Communist Party. In January 1928, Trotsky was deported by Soviet leader Joseph Stalin to Alma-Ata in remote Soviet Central Asia. He lived there in internal exile for a year before being banished from the USSR forever by Stalin.

He was received by the government of Turkey and settled on the island of Prinkipo, where he worked on finishing his autobiography and history of the Russian Revolution. After four years in Turkey, Trotsky lived in France and then Norway and in 1936 was granted asylum in Mexico. Settling with his family in a suburb of Mexico City, he was found guilty of treason in absentia during Stalin’s purges of his political foes. He survived a machine gun attack carried out by Stalinist agents, but on August 20, 1940, fell prey to Ramón Mercader, a Spanish communist who had won the confidence of the Trotsky household. The Soviet government denied responsibility, and Mercader was sentenced to 20 years in prison by Mexican authorities.