The Chahars (Khalkha Mongolian: Цахар, Tsahar; simplified Chinese: 察哈尔部; traditional Chinese: 察哈爾部) are a subgroup of Mongols that speak Chakhar Mongolian and predominantly live in southeastern Inner Mongolia, China. When Outer Mongolia declared its independence from the Qing in 1911, 100 households under former vice-governor Sumya fled from Xinjiang via the Russian border to Mongolia. They were resettled by the Khalkha in the west of Kyakhta. Sumiya and his Tsahars contributed to the revolution of 1921. They are known as the Selenge's Tsahar since settled in Selenge.