As a result, the Treaty of Berlin (1878), under the supervision of Otto von Bismarck of Germany and Benjamin Disraeli of United Kingdom, revised the earlier treaty, and scaled back the proposed Bulgarian state. A widely autonomous Principality of Bulgaria was created, between the Danube and the Stara Planina range, with its seat at the old Bulgarian capital of Veliko Turnovo, and including Sofia. This state was to be under nominal Ottoman sovereignty but was to be ruled by a prince elected by a congress of Bulgarian notables and approved by the Powers. They insisted that the Prince could not be a Russian, but in a compromise Prince Alexander of Battenberg, a nephew of Tsar Alexander II, was chosen. An autonomous Ottoman province under the name of Eastern Rumelia was created south of the Stara Planina range, whereas Macedonia was returned under the sovereignty of the Sultan. 19th century The Bulgarians adopted an advanced democratic constitution, and power soon passed to the Liberal Party led by Stefan Stambolov. Prince Alexander had conservative leanings, and at first opposed Stambolov's policies, but by 1885 he had become sufficiently sympathetic to his new country to change his mind, and supported the Liberals. He also supported the Unification of Bulgaria and Eastern Rumelia, which was brought about by a coup in Plovdiv in September 1885. The Powers did not intervene because of the power struggles between them. Shortly after, Serbia declared war on Bulgaria in the hope of grabbing territory while the Bulgarians were distracted. The Bulgarians defeated them at Slivnitsa, pushed the Serbian army into Serbia and succeeded to re-conquer the seized by the Berlin Treaty Bulgarian populated towns of Pirot and Vranya, but they were given back to Serbia with the Treaty of Bucharest in 1886. These events made Alexander very popular in Bulgaria, but Russia was increasingly dissatisfied at the liberal tendencies under his reign. In August 1886 they fomented a coup, in the course of which Alexander was forced to abdicate and was exiled to Russia. Stambolov, however, acted quickly and the participants in the coup were forced to flee the country. Stambolov tried to reinstate Alexander, but strong Russian opposition forced the prince to abdicate again. In July 1887 the Bulgarians elected Ferdinand of Saxe-Coburg-Gotha as their new Prince. Ferdinand was the "Austrian candidate" and the Russians refused to recognise him. Ferdinand initially worked with Stambolov, but by 1894