what happened at the beginning of world war 1
World War I On 28 June 1914, Gavrilo Princip, a Bosnian Serb supporter of Yugoslav nationalism, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand while he was visiting Sarajevo. The instability caused by competing Russian and Austro-Hungarian objectives in the Balkans meant this led to a diplomatic crisis, which ended with Austria-Hungary issuing an ultimatum to Serbia. [12][13] Interlocking alliances meant the crisis ultimately involved all the major European powers as well as their respective colonial empires and the conflict rapidly spread across the globe.