The First World War is one of the largest wars in human history.
The formal reason for the war was the events in Sarajevo, where on June 28, 1914, the Bosnian Serb Gavrilo Princip killed the heir to the Austro-Hungarian throne, Archduke Ferdinand, and his morganatic wife Sofia Chotek. The countries participating in the First World War were divided into two opposing camps: Central Powers: German, Austro-Hungarian, Ottoman Empires and the Bulgarian Kingdom; Entente: Russian Empire, British Empire, French Republic.
In total, during the war years, more than 70 million people were mobilized in the armies of the warring countries, including 60 million in Europe, of which 9 to 10 million died. The number of civilian casualties, according to various estimates, is in the range from 7 to 12 million people, of which about 1 million died as a result of hostilities; about 55 million people were injured. The First World War served as the prologue and detonator of major revolutions, including the February and October 1917 in Russia and the November 1918 in Germany.