The First World War was not “the war to end all wars.” It was, instead, the beginning of the kind of modern mass violence that would scar the century. For the first time, the armies of Europe used such tools of slaughter as the flamethrower, poison gas, the tank, and war planes.
The war’s catalyst came in the summer of 1914, when Gavrilo Princip, a radicalized Yugoslav nationalist, fired two shots into a car in a Sarajevo side street, killing the Austrian Archduke Franz Ferdinand and his wife. In the following weeks, all knots of European diplomacy tightened, and a net of alliances dragged the continent into a war that would last for the next four years. 19 million people died, more than half of them civilians.
The gallery below offers a window into the fighting in Europe during the first truly modern war – a conflict that, whether we realize it or not, shaped the dimensions and norms of the world we live in today: