World War I also known as the First World War, or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918.
The trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914.
More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. Over nine million combatants and seven million civilians died as a result of the war.
It was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved.
Failures to learn the lessons in the world War I let to the Second World War (1939-1945).
It is a must watch documentary for an UPSC aspirant to get a deeper understanding in GS Mains Paper I. (World History)