After entering the University of Buenos Aires to study medicine, Ernesto began travelling around Latin America. Taking a year off from their studies, he and his friend Alberto Granado decided to see South America on a motorcycle, and then volunteer at a colony in Peru. That trip became the basis of a successful movie in 2004, The Motorcycle Diaries.
The trip was eye-opening in a number of ways. It exposed the young man to widespread poverty and oppression in Latin America. Influenced by Marxist literature, this is when he came up with a solution to counter all the injustice he came across -- armed revolution.
Returning to Argentina, Ernesto completed his medical studies before resuming his travels across Central and South America.
In 1953, he decided to set up base in Guatemala, to familiarise himself with reforms implemented there by then president, Jacobo Arbenz Guzman. A letter to his aunt revealed his intention: 'I will perfect myself and accomplish whatever may be necessary in order to become a true revolutionary'.
While helping out at a local hospital, he also began spending time with a group of Cuban exiles linked to Fidel Castro. Interestingly, it is during this time he got his famous nickname, 'Che' -- the Argentine equivalent of 'hey' or 'pal'.
Eventually, when the CIA overthrew the Arbenz regime, Guevara was convinced the United States was an imperialist power. It only cemented his view that armed struggle was the only solution.
Photograph: With Cuban leader, Fidel Castro (left) during a meeting in Havana in the 1960s. Photograph: STF/AFP/Getty Images
Also read: The Castro I knew