The First World War began in 1914 after the assassination of Archduke Franz Ferdinand of Austria-Hungary by Serbian nationalists. Major European powers chose sides and joined the war in support of either the Allied powers or the Central powers. The war resulted in immense losses and casualties over four years before ending in 1918 with the defeat of the Central powers. Millions of soldiers and civilians lost their lives during this global conflict that reshaped international geopolitics.