What event sparked World War 1

The event that was widely acknowledged to have sparked the outbreak of World War I occurred on June 28, 1914, when Archduke Franz Ferdinand, heir to the Austro-Hungarian Empire, was shot to death with his wife by the Bosnian Serb nationalist Gavrilo Princip in Sarajevo.

The immediate origins of the war, however, lay in the decisions taken by statesmen and generals during the July Crisis of 1914 caused by the assassination of Archduke Franz Ferdinand and his wife Sophie by Gavrilo Princip, an ethnic Serb and Yugoslav nationalist from the group Young Bosnia, which was supported by the Black Hand, a nationalist organization in Serbia.