of Western Eurasia. From the 8th century, the Byzantine sources often mention the Onoğurs in close connection with the Bulgars. Agathon (early 8th century) wrote about the nation of Onoğurs Bulğars. Nikephoros I (early 9th century) noted that Kubrat was the lord of the Onoğundurs; his contemporary Theophanes referred to them as Onoğundur–Bulğars. Constantine VII (mid-10th century) remarked that the Bulğars formerly called themselves Onoğundurs. 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 Nándor Fejérvár, 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 later Oğuric (prothetic v-). Scholars consider it unclear how this union came about, viewing it as a long process in which a number of different groups were merged. During that time, the Bulgars may have represented a large confederation including the remnants of Onoğurs, Utigurs and Kutrigurs among others. Old Great Bulgaria The Turk rule weakened sometime after 600, allowing the Avars to reestablish the control over the region. As the Western Turkic Khaganate declined, finally collapsing in the middle of the 7th century, it was against Avar rule that the Bulgars, recorded as Onoğundur–Bulğars, reappeared. They revolted under their leader Kubrat (c. 635), who seems to have been prepared by Heraclius (610–641) against the Sasanian–Avar alliance. With his uncle Organa in 619, Kubrat had been baptized in Constantinople. He founded the Old Great Bulgaria (Magna Bulgaria), also known as Onoğundur–Bulğars state, or Patria Onoguria in the Ravenna Cosmography. Little is known about Kubrat's activities. It is considered that Onogur Bulgars remained the only steppe tribes in good relations with the Byzantines. His date of death is placed between 650 and 663 AD. According to Nikephoros I, Kubrat instructed his five sons to "never separate their place of dwelling from one another, so that by being in concordance with one another, their power might thrive". Subsequent events proved Old Great Bulgaria to be only a loose tribal union, as there emerged