The book "Guerrilla Warfare" was written by the Marxist revolutionary Che Guevara. He started writing it immediately after the success of the Cuban Revolution and it was published in 1961. Soon, the book gained a referential scientific value for all revolutionaries and guerrilla fighters in different countries around the world. Guevara's aim was for it to be a practical scientific reference for guerrilla warfare for all revolutionary movements in Latin America, Africa, and Asia. He detailed and expounded his theory - the foco theory - in it. However, the book was also studied by counter-revolutionaries and reactionaries. He put forward his famous theory that guerrilla warfare should only be used against dictatorial systems, except for political liberation operations and the achievement of civil rights from any guerrilla war or violent or armed revolutionary movements. Guevara dedicated the book to his comrade-in-arms and friend Camilo Cienfuegos for him to review and comment on, but unfortunately, fate decided that Camilo would die in an accident in the Atlantic Ocean and he passed away there.