https://en.wikipedia.org/wiki/Bulgar_language
Bulgar (also known as Bulghar, Bolgar, or Bolghar) is an extinct Oghur Turkic language spoken by the Bulgars.. The name is derived from the Bulgars, a tribal association that established the Bulgar state known as Old Great Bulgaria in the mid-7th century, giving rise to the Danubian Bulgaria by the 680s. While the language was extinct in Danubian Bulgaria (in favour of Old …