Fidel Castro changed his country and the world. He gave up a career as a lawyer, chose guerrilla warfare, and overthrew the corrupt dictator Fulgencio Batista with his rebel army in 1958/1959. When the CIA organized an invasion in 1961, he declared the Cuban Revolution to be socialist. On the world stage, he became the voice of the non-aligned countries, also providing military support for the fight against the apartheid regime in South Africa and sending educators and medical professionals to the most remote parts of the world. His vision of a fairer society remains relevant for millions of people in the global south. Volker Hermsdorf describes the emergence of Fidel Castro's political personality and outlines the development of his thinking. Castro was at once a visionary, pragmatic revolutionary, strategist, and statesman.