Hulunbuir or Hulun Buir (, Kölün buyir, Mongolian Cyrillic: Хөлөнбуйр, Khölönbuir; , Hūlúnbèi'ěr) is a region that is governed as a prefecture-level city in northeastern Inner Mongolia, China. Its administrative center is located at Hailar District, its largest urban area. Major scenic features are the high steppes of the Hulun Buir grasslands, the Hulun and Buir lakes (the latter partially in Mongolia), and the Khingan range. Hulun Buir borders Russia to the north and west, Mongolia to the south and west, Heilongjiang province to the east and Hinggan League to the direct south. Hulunbuir is a linguistically diverse area: next to Mandarin Chinese, Mongolian dialects such as Khorchin and Buryat, the Mongolic language Daur, and some Tungusic languages, including Oroqen and Solon, are spoken there. History During the Qing Dynasty (1644–1912), Hulunbuir was part of Heilongjiang province. The 1858 Treaty of Aigun established today's approximate Sino-Russian border, at a great loss to Heilongjiang's territory. In 1901, the Chinese Eastern Railway linked Hulunbuir to the rest of northeast China and to Russian Far East. From 1912 to 1949, during the Republic of China (ROC) period, Hulunbuir was part of Xing'an and Heilongjiang provinces. In winter 1912, the Barga Mongol people of Hulunbuir expelled the Chinese troops and administration and proclaimed the independence of Barga (Hulunbuir); afterwards they declared allegiance to the Bogdo Khan of Mongolia; an agreement between the Russian Empire and the ROC on November 6/October 24, 1915 designated Hulunbuir a "special" region under direct subordination to the Central Government of China, but in practice Russia had partial control over day-to-day administration and economy. In 1929, the Soviet Union broke this agreement and invaded Hulunbuir. After the Japanese invasion of China, Hulunbuir became part of the Japanese puppet state Manchukuo, which was not recognized by the Chinese. In the Chinese Civil War, the Communist Party of China gained the support of Inner Mongol leaders like Ulanhu by promising the irredentist expansion of Inner Mongolia into areas that had majorities of Han and Manchu peoples. After the 1949 Communist revolution, Hulunbuir was annexed into Inner Mongolia, but the region kept economic ties to the rest of the northeast via the Chinese Eastern Railway. During the Cultural Revolution, the parts of historical Manchuria inside Inner Mongolia were briefly restored to their original provinces; Hulunbuir was given back to Heilongjiang from 1969 to 1979. Until October 10, 2001, Hulunbuir was administered as a