what was the outbreak of world war 1
Between 1908 and 1914, the Balkans had been destabilised by the combination of a weakened Ottoman Empire, the 1912 -- 1913 Balkan Wars and competing Russian and Austro-Hungarian objectives. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July Crisis. On 23 July, Austria-Hungary issued an ultimatum to Serbia; interlocking alliances quickly drew in all the major European powers with their respective colonial empires and the conflict rapidly spread across the globe.