The people who speak the Fuyu Kyrgyz language originated in the Yenisei region of Siberia but were relocated into the Dzungar Khanate by the Dzungars, and then the Qing moved them from Dzungaria to northeastern China in 1761, and the name may be due to the survival of a common tribal name.

[8] Sibe Bannermen were stationed in Dzungaria while Northeastern China (Manchuria) was where some of the remaining Öelet Oirats were deported to.

It is now spoken in northeastern China's Heilongjiang province, in and around Fuyu County, Qiqihar (300 km northwest of Harbin) by a small number of passive speakers who are classified as Kyrgyz nationality.

The Finnish linguist Matthias Castrén, who travelled through northern and Central Asia between 1845 and 1849, wrote a treatise on the Koybal dialect, and recorded an epic.

The ninth volume, provided with a Russian translation, was prepared by Radloff's student Katanov, who was a Sagay himself, and contains further Khakas materials.

Officially considered a dialect of Khakas, its speakers regard Xyzyl as a separate language of its own.