The Khakas are a Turkic indigenous people of Siberia, who live in the republic of Khakassia, Russia. They speak the Khakas language.
The Khakhassian people are direct descendants of various ancient cultures that have inhabited southern Siberia, including the Andronovo culture, Samoyedic peoples, the Tagar culture, and the Yenisei Kirghiz culture.
Despite the name, the Fuyu Kyrgyz language is not related to the Kyrgyz language, which is of Kipchak origin. The Fuyu Kyrgyz language is more similar to the Yughur language and the Abakan Turkic languages.
The name Khakas is generally thought to be a corruption of Khyagas of the Chinese chronicles. Note also the probable connection of Khakas to Xaas, the (former) self-designation of the Qača clan. Some Khakas-speaking people apparently disapprove of the ethnonym Khakas, preferring to use their self-designation Tadar (i.e. Tatar), a name in all likelihood actually given to these and all other Turkic-speaking ethnolinguistic groups of south-central Siberia by an earlier group of Russians. The ethnonym Khakas, also the name of one of the two literary languages in the area, was adopted by the local intelligentsia after 1917.
The Yenisei Kirghiz were made to pay tribute in a treaty concluded between the Dzungars and Russians in 1635. The Dzungar Oirat Kalmyks coerced the Yenisei Kirghiz into submission.
Some of the Yenisei Kirghiz were relocated into the Dzungar Khanate by the Dzungars, and then the Qing moved them from Dzungaria to northeastern China in 1761, where they became known as the Fuyu Kyrgyz. Sibe Bannermen were stationed in Dzungaria while Northeastern China (Manchuria) was where some of the remaining Öelet Oirats were deported to. The Nonni basin was where Oirat Öelet deportees were settled. The Yenisei Kirghiz were deported along with the Öelet. Chinese and Oirat replaced Oirat and Kirghiz during Manchukuo as the dual languages of the Nonni-based Yenisei Kirghiz.
In the 17th century, the Khakas formed Khakassia in the middle of the lands of Yenisei Kirghiz, who at the time were vassals of a Mongolian ruler.