On June 28, 1914, Gavrilo Princip, an agent of the Serbian Black Hand secret society, assasinated Archduke Franz Ferdinand, heir to the Austria-Hungary throne. This set the wheels turning that started the first World War. Along with revolutionary unrest in many European countries.
The same day of Archduke Franz Ferdinand’s assassination the Austrian government retaliated by declaring war on Serbia. Russia’s Emperor, Nicholas II was pressured by Russia’s military to defend Serbia. So after much regrets he declared