Also known as the League of the Three Emperors (1872)
Bismarck's aim for forming this League was to isolate France by making friends with Austria and Russia. The partners were Kaiser William I of Germany, Czar Alexander II of Russia and Emperor Francis Joseph of Austria. These three rulers agreed: (i) to maintain the existing territorial arrangements in Europe; (ii) to resist the spread of revolutionary (e.g. socialist) movements; and (iii) to consult one another if any international difficulties arose.
France was being diplomatically isolated. But the underlying weakness of this personal understanding between the three emperors was the rivalry between Austria and Russia over the Balkan Peninsula. Both sought to dominate the Balkans. It was difficult for Bismarck to keep them in the same camp.
Dual Alliance 1879 *
The Congress of Berlin 1878
Rivalry between Austria and Russia in the Balkans came to a head in 1877-78. In 1875, five Balkan states revolted against the Turkish rule. Russia supported the Balkan states and defeated Turkey. On March 8, 1878, Turkey was forced to sign the Treaty of San Stefano, in which an independent, Big Bulgaria was created. Seeing that this Bulgaria would be a Russian puppet, Austria intervened, backed up by Britain, the traditional rival of Russia in the eastern Mediterranean. Bismarck volunteered to act as an "honest broker" and called the Congress of Berlin to settle the Balkan problems. At this Congress, Germany sided with Austria and Britain. Russia had to give up the Treaty of San Stefano and sign the Treaty of Berlin. The Treaty split Bulgaria into three parts (Bulgarian Proper was to be independent, Eastern Rumelia and Macedonia were to be ruled under Turkish sovereignty.) and brought Bosnia and Herzegovina under Austrian military occupation (but not annexation). Russia felt diplomatically humiliated. The anger of Russia turned against Bismarck because he chaired the Congress.