Some scholars suggest Hunnic had strong ties with Bulgar and to modern Chuvash[7] and refer to this extended Oghuric grouping as separate Hunno-Bulgar languages.
[8] However, such speculations are not based on proper linguistic evidence, since the language of the Huns is almost unknown except for a few attested words and personal names.
[26][27] The shift from s to š operates before i, ï, and iV, and Vladimir Dybo calls the sound change the "Bulgar palatalization".
[28] Denis Sinor believed that the differences noted above suggest that the Oghur-speaking tribes could not have originated in territories inhabited by speakers of Mongolic languages, given that Mongolian dialects feature the -z suffix.
[37][38] The Onogurs were one of the first Oghuric Turkic tribes that entered the Ponto-Caspian steppes as the result of migrations set off in Inner Asia.
[48] Leo I the Thracian granted Ernak the lands of the treacherous Karadach's Akatziroi roughly corresponding to 20th century Ukraine.
Later kings of the Onogur Huns included Grod, Mugel and Sandilch, whose Utigurs were engaged in a civil war against the Kutrigurs of Khinialon.
The origin of the Kutrigurs and Utigurs, who lived in the vicinity of the Onoghurs and Bulgars, and their mutual relationship, is considered obscure.
[49][50] Scholars are unsure how the union between Onoghurs and Bulgars formed, imagining it as a long process in which a number of different groups merged.
[51][52] During that time, the Bulgars may have represented a large confederation of which the Onoghurs formed one of the core tribes,[52] together with the remnants of the Utigurs and Kutrigurs, among others.
[53] Jordanes in Getica (551) mentioned that the Hunuguri (believed to be the Onoghurs) were notable for the marten skin trade.
Avgar, sabir, burgar, alan, kurtargar, avar, hasar, dirmar, sirurgur, bagrasir, kulas, abdel and hephtalit are thirteen peoples, who live in tents, earn their living on the meat of livestock and fish, of wild animals and by their weapons (plunder)".
[54][59] The Onoghurs (Oghurs), in the 6th and 7th century sources, were mentioned mostly in connection with the Avar and Göktürk conquest of Western Eurasia.
[60] According to the 6th century Menander Protector, the "leader of the Οὐγούρων" had the authority of the Turk Yabgu Khagan in the region of Kuban River to the lower Don.
[61] In early 7th century Theophylaktos Simokattes recorded that certain Onoghur city Βακάθ was destroyed by an earthquake before his lifetime.
[42] Simokattes in the Letter of the Turk Qaγan (Tamgan) to the Emperor Maurikios recorded a complex notice: "...the Qaghan set off on another undertaking and subjugated all the Ὀγώρ.
[62] Simokattes also recounts "when the Ogor, then, were brought completely to heel, the Qaγan gave over the chief of the Κὸλχ (Kolx[61]) to the bite of the sword", shows Oghurs resistance toward Turkic authority.
[68] Onoghur-Bulgars who settled on the Volga river in the 7th century AD and converted to Islam in 922 during the missionary work of Ahmad ibn Fadlan, inhabited the present-day territory of Tatarstan.
This association was previously mirrored in Armenian sources, such as the Ashkharatsuyts, which refers to the Olxontor Błkar, and the 5th century History by Movses Khorenatsi, which includes an additional comment from a 9th-century writer about the colony of the Vłĕndur Bułkar.
Marquart and Golden connected these forms with the Iġndr (*Uluġundur) of Ibn al-Kalbi (c. 820), the Vnndur (*Wunundur) of Hudud al-'Alam (982), the Wlndr (*Wulundur) of Al-Masudi (10th century) and Hungarian name for Belgrad Nándorfehérvár, the nndr (*Nandur) of Gardīzī (11th century) and *Wununtur in the letter by the Khazar King Joseph.
All the forms show the phonetic changes typical of late Oghuric (prothetic w-; o- > wo-, u-, *wu-).