Rückversicherungsvertrag
The Treaty of Berlin (1878) made Russia feel cheated of its gains in the Russo-Turkish War. Its key role in European diplomacy was not, however, forgotten by Bismarck. A more formal Three Emperors' Alliance was concluded on 18 June 1881. It lasted for three years, and was renewed at Skierniewice in 1884, but lapsed in 1887. Both alliances ended because of conflicts between Austria-Hungary and Russia in the Balkans. To preserve a common understanding with Russia, Germany signed the mutual Reinsurance Treaty in 1887.