The Eastern Question
Ever since the Ottoman (Turkish) Empire, which had dominated the eastern Mediterranean and much of eastern Europe since the 15th century, went into decline (it had reached its height during the reign of Suleyman the Magnificent [1520-66]), the western powers (France, England and Germany), the Austro-Hungarians (Habsburgs) and the Russians had been grappling with the Eastern Question, i.e., what power would fill the vacuum created by the waning Ottoman Empire? The states on the Balkan Peninsula, positioned at the interface between Russia, Turkey and Eastern Europe, especially became the focus of complex international maneuvering and "intrigues."
The Concert of Europe
The Concert of Europe, formulated in 1815 as a mechanism to enforce the decisions of the Congress of Vienna, was composed of the Quadruple Alliance: Russia, Prussia, Austria and Great Britain. Its main priorities were to establish a balance of power, thereby preserving the territorial status quo, and to protect "legitimate" governments. Headed by Prince Metternich of Austria, the Concert of Europe was one of the first serious attempts in modern times to establish an international society to maintain the peace. This made it a significant event in world history, even though it only lasted for a few decades.
The Crimean War
Russia and Turkey had experienced ongoing conflicts since the 18th century and Russia had gained vast portions of the Ottoman Empire. This trend, which greatly concerned the other European powers (who wanted a strong Turkey in order to keep the Russians in check), led to the Crimean War (1853-56) where Britain (concerned that Russia was seeking to control the Dardanelles and thus threaten England's Mediterranean sea routes) and France entered the war between Russia and Turkey on the side of the Turks.
The Treaty of Paris
The Treaty of Paris, reached in 1856, firmly centered the great burden imposed on the almost lifeless balance of power. Russia was no longer allowed to have their battleships in the Black Sea or in the Straits, which left Russia with a southern border in need of defense. Now Russia was at a disadvantage with the other powers in the Concert of Europe, and no longer motivated to uphold its goals.
In 1877, following uprisings against Turkish overlords in several Balkan states (Serbia, Montenegro, Bosnia and Hercegovina), Russia attacked and defeated Turkey. By the terms of the Treaty of San Stefano (1878) Turkey was forced to relinquish much of its Balkan holdings: (1) Serbia, Romania and an enlarged Montenegro received independence; (2) an autonomous and greatly augmented Bulgaria (which had been under Turkish rule since the 14th century) emerged that stretched from Serbia to the Black Sea and included extensive territory in Thrace, abutting th Aegean Sea. Thus these Balkan states which had been under Turkish control now came under the Russian sphere of influence.
Concerned with Russia becoming more of a force in the Balkans, the other European powers called for a summit to ratify a new treaty. Russia could ill afford another Crimean War and thus acceded to the request for a ratification of the San Stefano Treaty.
Congress of Berlin
The Congress of Berlin, by an agreement signed July 13, 1878 by the six great powers (Austro-Hungary, France, Italy, Germany [represented by Bismarck], Russia and Great Britain) on one side and the Ottoman Empire on the other, changed the terms of the Treaty of San Stefano: (1) Bulgaria was divided into thirds with only the territory north of the Balkan Mountains retaining the autonomy granted under the Treaty of San Stefano; (2) Bosnia and Hercegovino were placed under Austrian control; (3) Serbia and Montenegro were recognized as independent; (4) the sanjak of Novi Pazar, in SW Serbia, was under Austrian control; (5) Macedonia was left under Turkish control; (6) Russia annexed Bessarabia; (7) Britain controlled Cyprus; (8) Crete, Thessaly and parts of Macedonia went to Greece.
The Congress of Berlin dashed the nationalist aspirations of the smaller Balkan states. Through the machinations of the European powers, the Balkan states remained fragmented, which enured to the benefit of the European powers. Had the terms of the Treaty of San Stefano stood, the newly independent Balkan states would have most likely fallen under Russian influence, shifting the delicate balance of power in the region. According to the noted European historian Carlton J.H. Hayes, "If before 1878 the Eastern Question concerned one 'sick man' [Turkey], after 1878 it involved a half-dozen maniacs. For the Congress of Berlin drove the Balkan peoples mad."