The precursor to the liberation in 1878 was an unsuccessful uprising in 1876. The Bulgarians, at this point, were ill prepared for war, politically and strategically. Thousands of Bulgarians were killed in April of that year. Soon thereafter Turkish reprisals followed. Fifteen thousand Bulgarians were massacred in Plovdiv alone. The savagery of these reprisals was so brutal that Western public leaders spoke out in protest. The governments of the West, however, fearing an increased Russian penetration in the area, refused to act against the Turks. Although the revolution of 1876 had met with failure, it had succeeded in loosening the Turkish grip on the country and in increasing the feeling of the Russians that the time to attack was imminent. Finally, after the Russo-Turkish war of 1877, the Russians invaded Bulgaria, liquidating the Turkish army by March 1878. In these battles for Bulgarian liberation, the Russians lost over 200,000 lives, a sacrifice the Bulgarians never failed to recognize. The results of 1878 were mixed, and the outcome of the original peace treaty was reversed within five months of its signing. Bulgaria became an autonomous tributary of the Turkish sultan; complete independence was not established until 1908. The original peace treaty, the Treaty of San Stefano, signed on March 3, 1878, granted Bulgaria additional territories, including Thrace and the much-valued Macedonia. This treaty was reversed, primarily because of Western fear of Russian encroachment, by the Congress of Berlin; the Treaty of Berlin, signed on July 13, 1878, unlike the Treaty of San Stefano, delimited Bulgarian territories. The Bulgarians were forced to give Thrace and Macedonia back to the Turks. Bulgaria itself was carved into two separate entities: the principality of Bulgaria, including northern Bulgaria and Sofia, and eastern Rumelia, or southern Bulgaria. LIBERATION AND ITS AFTERMATH Although the 1877-78 war freed Bulgaria from Turkish rule, the outcome of the Congress of Berlin once again denied to Bulgaria the land that it perceived to be rightfully Bulgarian, thus setting the tone for an irredentist foreign policy that lasted through World War II. Because the West, particularly Great Britain, played a significant role in carving up the Balkans, and Bulgaria in particular, in hopes of curbing Russian power, many historians speculate that Bulgaria's alliances with Germany in both World War I and World War II were products of irredentist sentiment that grew out of the Treaty of Berlin. Bulgaria moved to recapture its lost territory only seven years after the Treaty of Berlin. In 1885 it annexed eastern Rumelia--or southern Bulgaria--by means of a military coup. The British were in favor of the annexation as it represented an obstacle to Russian ambitions in the Balkans; the Russians quite naturally were disturbed by the act. This was the first in a series of Bulgarian moves designed to reestablish earlier boundaries.