Russia had, however, steadily been making her preparations, and, Turkey having refused to discontinue hostilities against Montenegro, on April 24, 1877, war was declared by the Emperor Alexander II, whose patience had become exhausted; he was joined by Prince Charles of Rumania, who saw that by doing so he would be rewarded by the complete emancipation of his country, then still a vassal-state of Turkey, and its erection into a kingdom.  At the beginning of the war all went well for the Russians and Rumanians, who were soon joined by large numbers of Bulgarian insurgents; the Turkish forces were scattered all over the peninsula.  The committee of Bucarest transformed itself into a provisional government, but the Russians, who had undertaken to liberate the country, naturally had to keep its administration temporarily in their own hands, and refused their recognition.  The Turks, alarmed at the early victories of the Russians, brought up better generals and troops, and defeated the Russians at Plevna in July.  They failed, however, to dislodge them from the important and famous Shipka Pass in August, and after this they became demoralized and their resistance rapidly weakened.  The Russians, helped by the Bulgarians and Rumanians, fought throughout the summer with the greatest gallantry; they took Plevna, after a three months’ siege, in December, occupied Sofia and Philippopolis in January 1878, and pushed forward to the walls of Constantinople.

The Turks were at their last gasp, and at Adrianople, in March 1878, Ignatiyev dictated the terms of the Treaty of San Stefano, by which a principality of Bulgaria, under the nominal suzerainty of the Sultan, was created, stretching from the Danube to the Aegean, and from the Black Sea to Albania, including all Macedonia and leaving to the Turks only the district between Constantinople and Adrianople, Chalcidice, and the town of Salonika; Bulgaria would thus have regained the dimensions it possessed under Tsar Simeon nine hundred and fifty years previously.

This treaty, which on ethnological grounds was tolerably just, alarmed the other powers, especially Great Britain and Germany, who thought they perceived in it the foundations of Russian hegemony in the Balkans, while it would, if put into execution, have blighted the aspirations of Greece and Serbia.  The Treaty of Berlin, inspired by Bismarck and Lord Salisbury, anxious to defend, the former, the interests of (ostensibly) Austria-Hungary, the latter (shortsightedly) those of Turkey, replaced it in July 1878.  By its terms Bulgaria was cut into three parts; northern Bulgaria, between the Danube and the Balkans, was made an autonomous province, tributary to Turkey; southern Bulgaria, fancifully termed Eastern Rumelia (Rumili was the name always given by the Turks to the whole Balkan peninsula), was to have autonomous administration under a Christian governor appointed by the Porte; Macedonia was left to Turkey; and the Dobrudja, between the Danube and the Black Sea, was adjudged to Rumania.