Triple Alliance was a defense agreement among Austria-Hungary, Germany, and Italy. It lasted from 1882 until 1915. The three countries agreed to help one another against attacks by two or more great powers. In addition, Austria-Hungary and Germany agreed to help Italy in case of an attack by France alone, and Italy agreed to help Germany if France attacked Germany.
The text of the alliance was secret, but its existence soon became known. It was renewed several times, sometimes with modifications. Despite the alliance, Italy and Austria-Hungary remained divided by Italy’s desire for the Trentino and Trieste districts, in what is now northeastern Italy. Many Italians lived in Trentino and Trieste, but the regions were ruled by Austria.
When World War I began in 1914, Italy remained neutral. This did not violate the terms of the Triple Alliance because Austria-Hungary and Germany had started the fighting. But in 1915, Italy made a secret agreement with the Triple Entente—an alliance of France, Russia, and the United Kingdom that opposed Austria-Hungary and Germany in the war. Italy pledged to fight on the side of the Triple Entente, and the entente members promised that Italy would get Trentino, Trieste, and other territories after the war. Italy declared war on Austria-Hungary in 1915. Germany then broke off relations with Italy, bringing the Triple Alliance to an end.
See also Bismarck, Otto von (Bismarck’s diplomacy) ; Italy (World War I) World War I (A system of military alliances) (The Italian Front) .
