The Khitan people (Khitan small script:, Chinese: 契丹; pinyin: Qìdān) were a nomadic people from Northeast Asia who, from the 4th century, inhabited an area corresponding to parts of modern Mongolia, Northeast China and the Russian Far East.
As proto-Mongols they spoke the Khitan language, which appears to be related to the Mongolic languages. During the Liao dynasty, they dominated a vast area of Siberia and northern China. After the fall of the Liao dynasty in 1125 following the Jurchen invasion, many Khitans followed Yelü Dashi's group westward to establish the Qara Khitai, or Western Liao dynasty, in Central Asia, which lasted several decades before falling to the Mongol Empire in 1218. Other regimes founded by the Khitans included the Northern Liao, Eastern Liao and Later Liao in China, as well as the Qutlugh-Khanid dynasty in Persia. Some Kyrgyz people show a genetic connection to the Khitan or are descendants of them.
There is no consensus on the etymology of the name of Khitan. There are basically three speculations. Feng Jiasheng argues that it comes from the Yuwen chieftains' names. Zhao Zhenji thinks that the term originated from Xianbei and means "a place where Xianbei had resided". Japanese scholar
Otagi Matsuo believes that Khitan's original name was "Xidan", which means "the people who are similar to the Xi people" or "the people who inhabit among the Xi people".
The term "Khitai" came to mean "China" in Turkic. It was introduced to medieval Europe by Islamic and Russian sources becoming "Cathay". In the modern era, the word is still used by the Uyghurs in China's Xinjiang region. The Han Chinese consider its use to be pejorative and the Chinese government has tried to ban its use.