三帝同盟
Anxious about Balkan instability and Russian aggression, and to counter French interests in Europe, Austria–Hungary forged a defensive alliance with Germany in October 1879 and in May 1882. In October 1882 Italy joined this partnership in the Triple Alliance largely because of Italy's imperial rivalries with France. Tensions between Russia and Austria–Hungary remained high, so Bismarck replaced the League of the Three Emperors with the Reinsurance Treaty with Russia to keep the Habsburgs from recklessly starting a war over Pan-Slavism. The Sandžak-Raška / Novibazar region was under Austro-Hungarian occupation between 1878 and 1909, when it was returned to the Ottoman Empire, before being ultimately divided between kingdoms of Montenegro and Serbia.