it returned to Ottoman control for diplomatic reasons, Russia gaining only two border forts. During the Crimean War, an Ottoman garrison led by British officers, including General William Fenwick Williams, kept the Russians at bay during a protracted siege, but after the garrison had been devastated by cholera and food supplies were depleted, the town was surrendered to General Mouravieff in November 1855. The city's significance increased as the Ottoman and Russian empires contested its possession. The fortress was stormed by the Russians in the Battle of Kars during the Russo-Turkish War, 1877-78 under generals Loris-Melikov and Ivan Lazarev. Following the war, Kars was transferred to Russia by the Treaty of San Stefano. Kars became the capital of the Kars Okrug and larger Kars Oblast ("region"), comprising the okrugs ("districts") of Kars, Ardahan, Kagizman, and Olti, which was the most southwesterly extension of the Russian Transcaucasus. In the following years the Russians supported the fortification of Kars. From 1878 to 1881 more than 82,000 Muslims from formerly Ottoman-controlled territory migrated to the Ottoman Empire. Among those there were more than 11,000 people from the city of Kars. At the same time, many Armenians and Pontic Greeks (here usually called Caucasus Greeks) migrated to the region from the Ottoman Empire and other regions of Transcaucasia. According to the Russian census data, by 1897 Armenians formed 49.7%, Russians 26.3%, Caucasus Greeks 11.7%, Poles 5.3% and Turks 3.8%. World War I In the First World War, the city was one of the main objectives of the Ottoman army during the lost Battle of Sarikamish in the Caucasus Campaign. Russia ceded Kars, Ardahan and Batum to the Ottoman Empire under the Treaty of Brest-Litovsk on 3 March 1918. However, by then Kars was under the effective control of Armenian and non-Bolshevik Russian forces. The Ottoman Empire captured Kars on 25 April 1918, but under the Armistice of Mudros (October 1918) was required to withdraw to the pre-war frontier and Kars came under control of the First Republic of Armenia. The Ottomans refused to relinquish Kars; its military governor instead established a government, the Provisional National Government of the Southwestern Caucasus, led by Fahrettin Pirioglu, that claimed Turkish sovereignty over Kars and Turkic-speaking regions as far as Batumi and Alexandropol (Gyumri). Much of the region fell under the administrative control of Armenia in January 1919 but the pro-Turkish government remained in the city until a