The First World War

An assassination in Sarajevo activates a system of alliances, and by 1918 around 20 million are dead. Machine guns, artillery, gas and barbed wire produce static trench lines where offensives gain metres for hundreds of thousands of casualties. The Russian, German, Austro-Hungarian and Ottoman empires all fall. The peace imposed at Versailles in 1919 settles little, and Ferdinand Foch reportedly called it an armistice for twenty years.