Watch The Great War - 1914: The Causes of War

The First World War: On 28 June 1914 the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand, was assassinated.This triggered a series of events that led to world war, with the fighting taking place on land, at sea and in the air. The result was the collapse of four empires and the death of more than 15 million people. But the tragedy did not end there and after the war Europe was left so bitterly divided and driven by racial hatred that a second world war loomed on the horizon.