三帝同盟
In 1873, to isolate France and avoid a war on two fronts, Bismarck negotiated the League of the Three Emperors (German: "Dreikaiserbund") between Austria-Hungary, Russia and Germany. Concerned by Russia's victory in the 1877–1878 Russo-Turkish War and its influence in the Balkans, the League was dissolved in 1878, with Germany and Austria-Hungary subsequently forming the 1879 Dual Alliance; this became the Triple Alliance when Italy joined in 1882.