World War One was a watershed moment for ushering in the full barbarism and dramatically heightened scale of modern wars between major imperialist powers under capitalism. But how did it begin? While conventional re-tellings heavily accent the role of personalities and the murder of Franz Ferdinand, deeper social, economic and political forces meant that the clash of industrial capitalist powers was an imperative for the British, French and German ruling classes. These same forces and imperialist priorities continue to govern the international system between states today.