World War I began in 1914 as a result of a series of events including the assassination of Archduke Franz Ferdinand of Austria-Hungary. The assassination was carried out by Gavrilo Princip, a member of the nationalist group known as the Black Hand. The war was not started by one single person or country, but rather by a complex web of alliances, militarism, imperialism, and nationalism that had been building up in Europe for years.