West European powers, declared war. In early 1877, Russia came to the rescue of beleaguered Serbia when it went to war with the Ottoman Empire of 1877–1878. Within one year, Russian troops were nearing Constantinople, and the Ottomans surrendered. Russia's nationalist diplomats and generals persuaded Alexander II to force the Ottomans to sign the Treaty of San Stefano in March 1878, creating an enlarged, independent Bulgaria that stretched into the southwestern Balkans. Another significant result of the 1877-78 Russo-Turkish War in Russia's favour was the acquisition from the Ottomans of the provinces of Batum, Ardahan, and Kars in the South Caucasus, which were transformed into the militarily administered regions of Batum Oblast and Kars Oblast. To replace Muslim refugees who had fled across the new frontier into Ottoman territory the Russian authorities settled large numbers of Christians from an ethnically diverse range of communities in Kars Oblast, particularly the Greek Orthodox Georgians and Caucasus Greeks, and Christian but mainly non-Orthodox Armenians, all of whom hoped to achieve their own regional ambitions on the back of the Russian Empire. When Britain threatened to declare war over the terms of the Treaty of San Stefano, an exhausted Russia backed down. At the Congress of Berlin in July 1878, Russia agreed to the creation of a smaller Bulgaria. Russian nationalists were furious with Austria-Hungary and Germany for failing to back Russia, but the Tsar accepted a revived and strengthened League of the Three Emperors as well as Austro-Hungarian hegemony in the western Balkans. Russian diplomatic and military interests subsequently re-focussed on Central Asia, where Russia had quelled a series of uprisings in the 1870s, and Russia incorporated hitherto independent emirates into the empire. Britain renewed its concerns in 1881 when Russian troops occupied Turkmen lands on the Persian and Afghan borders, but Germany lent diplomatic support to Russian advances, and an Anglo-Russian war was averted. Meanwhile, Russia's sponsorship of Bulgarian independence brought negative results as the Bulgarians, angry at Russia's continuing interference in domestic affairs, sought the support of Austria-Hungary. In the dispute that arose between Austria-Hungary and Russia, Germany took a firm position toward Russia while mollifying the tsar with a bilateral defensive alliance, the Reinsurance Treaty of 1887 between Germany and Russia. Within a year, Russo-German acrimony led to Otto von Bismarck's forbidding further loans to Russia, and France replaced Germany as Russia's financier. When Wilhelm II dismissed Bismarck in 1890,