The Russo-Turkish War of 1877-78 ended with Russia's victory, forcing the opponent to agree to an armistice. The treaty, signed in San Stefano, included a preamble and 29 articles. Historians believe that this document played an important role in the liberation of the Balkan peoples from Ottoman rule.

Under the terms of the treaty, independence and territorial expansion were granted to Serbia, Montenegro, and Romania. An autonomy of Bulgaria was established within the Ottoman Empire, which was granted the right to its own army and government. Bosnia and Herzegovina could exist under similar conditions. Russia's connection with Turkey was limited to the payment of tribute. Additionally, Russia received Batum, Ardahan, Kars, Bayazet, and Southern Bessarabia, lost under the Paris Peace Treaty of 1856. Turkey also agreed to pay Russia 310 million rubles in tribute.

The terms of the treaty provoked a negative reaction from Western European countries, which feared an increase in Russia's influence in the Balkans. England and Austria-Hungary declared that the document violated the terms of the Paris Peace. The Russian government faced a dilemma: to consider the opinion of the West or to ignore it, risking a new war with a stronger opponent.

As a result of these reflections, an International Congress was held in Berlin in June-July 1878, attended by delegations from Russia, England, Austria-Hungary, Germany, France, Italy, and Turkey, as well as invited representatives from Greece, Iran, Romania, Montenegro, and Serbia. Austria-Hungary, fearing the strengthening of Russia in the Balkans and the formation of Bulgaria, a new Slavic state, was the main initiator of the gathering.

As a result of the congress, a treaty of 64 articles was signed, significantly altering the terms of the San Stefano treaty. Bulgaria was divided into two parts along the Balkan ridge: the northern part became an autonomous principality paying tribute to Turkey, while the southern part remained under Turkish administration with administrative autonomy. Turkey also received Macedonia, which had previously been part of Bulgaria. Serbia, Montenegro, and Romania lost part of their territories, while Bosnia and Herzegovina came under the occupation of Austria-Hungary. Russia returned the Alashkert Valley and the city of Bayazet to Turkey, retaining the mouth of the Danube, Kars, and Ardahan. Batumi became a free trade port.

Historians note that England, in gratitude for supporting Turkey, received Cyprus. The congress led to a weakening of Russia's position in the Balkans, which was forced to make concessions due to the threat of a new war that the empire sought to avoid. Austria-Hungary and England, which did not participate in the conflict of 1877-78, gained certain benefits after the congress. The head of the Russian delegation, Chancellor Alexander Gorchakov, later referred to the Berlin Congress as a black page in his career in a report to Emperor Alexander II.