The Bulgars (also Bulghars, Bulgari, Bolgars, Bolghars, Bolgari, Proto-Bulgarians) were Turkic semi-nomadic warrior tribes that flourished in the Pontic–Caspian steppe and the Volga region during the 7th century. They became known as nomadic equestrians in the Volga-Ural region, but some researchers believe that their ethnic roots can be traced to Central Asia.
During their westward migration across the Eurasian Steppe, the Bulgar tribes absorbed other tribal groups and cultural influences in a process of ethnogenesis, including Iranic, Finnic and Hunnic tribes. The Bulgars spoke a Turkic language, i.e. Bulgar language of Oghuric branch. They preserved the military titles, organization and customs of Eurasian steppes, as well as pagan shamanism and belief in the sky deity Tangra.
The Bulgars became semi-sedentary during the 7th century in the Pontic-Caspian steppe, establishing the polity of Old Great Bulgaria c. 630–635, which was defeated by the Khazar Empire in 668 AD. In c. 679, Khan Asparukh conquered Scythia Minor, opening access to Moesia, and established the Danubian Bulgaria – the First Bulgarian Empire, where the Bulgars became a political and military elite. They merged subsequently with established Byzantine populations, as well as with previously settled Slavic tribes, and were eventually Slavicized, thus forming the ancestors of modern Bulgarians.
The remaining Pontic Bulgars migrated in the 7th century to the Volga River, where they founded the Volga Bulgaria; they preserved their identity well into the 13th century. The modern Volga Tatars, Bashkirs and Chuvash people claim to have originated from the Volga Bulgars.
The etymology of the ethnonym Bulgar is not completely understood and difficult to trace back earlier than the 4th century AD. Since the work of Tomaschek (1873), it is generally said to be derived from Proto-Turkic root *bulga- ("to stir", "to mix"; "to become mixed"), which with the consonant suffix -r implies a noun meaning "mixed".