August 1914 - the trigger for the Great War that threw millions of men together from the mud of Flanders to the heights of Verdun: in all, one of the most tragic epochs of the bloody 20th century. Within these anonymous masses, struggling through hardship and sacrifice, some unknowns would discover in themselves the 'divine coupling of courage and fear' that would lead them to their vocations as leaders of men. Charles de Gaulle, Winston Churchill, Adolf Hitler, Benito Mussolini, George S. Patton: these 5 men, hardened in the crucible of the First World War, would become the great decision-makers of the war to come. The ordeal they went through would mark them profoundly and influence the course of their careers and, decisively, the course of history. For the first time, these five destinies are presented together in one work: an exceptional iconography and an essential document for understanding the history of both wars, and the history of the 20th century. Text in French.