World War I Begins

The assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo on 28 June 1914 initiated the July Crisis, a month of diplomatic manoeuvring among Austria-Hungary, Germany, Russia, France and Britain. The causes of World War I included the rise of the German Empire, which disturbed the long-standing balance of power in Europe, and the exacerbation of imperial rivalries, as reflected in new alliances and an arms race between the great powers. Austria-Hungary blamed Serbia and declared war on 28 July, and the Russian Empire mobilised in Serbia's defence. In early August Germany declared war on Russia and France, and the United Kingdom entered the war after Germany invaded Belgium. World War I, a global conflict between two coalitions, the Allies and the Central Powers, lasted from 28 July 1914 to 11 November 1918 and caused 15 to 22 million deaths. The collapse of the Russian, German, Austro-Hungarian and Ottoman empires resulted in new national boundaries and new independent states including Poland, Finland, the Baltic states, Czechoslovakia and Yugoslavia.