Bulgars

The Bulgars arrived in the Balkans in the 7th century from central Asia, but their exact origin is not entirely clear. The established theory is that the Bulgars are related to the Huns, and more distantly the Turks. However, this position is increasingly being challenged by a theory claiming Aryan-Pamirian origin for the Bulgars. Clues for this can be found in the advanced calendar and system of government of the early Bulgars.
The Bulgars were governed by hereditary khans. There were several aristocratic families whose members, bearing military titles, formed a governing class. Bulgars were monotheistic, worshipping a god called "Tangra".
The migration of Bulgars to the European continent started as early as the 2nd century when branches of Bulgars settled on the plains between the Caspian and the Black Sea. Between 351 and 389 AD, some of these crossed the Caucasus and settled in Armenia. They were eventually assimilated by the Armenians.
Swept by the Hunnish wave at the beginning of the 4th century, other numerous Bulgarian tribes broke loose from their settlements in central Asia to migrate to the fertile lands along the lower valleys of the Donets and the Don rivers and the Azov seashore. Some of these remained for centuries in their new settlements, whereas others moved on with the Huns towards Central Europe, settling in Pannonia.
In the 632 AD, the Bulgars, led by Khan Kubrat formed an independent state, often called Great Bulgaria, between the lower course of the Danube to the west, the Black and the Azov Seas to the south, the Kuban river to the east, and the Donets river to the north. The capital of the state was Phanagoria, on the Azov.
The pressure from peoples further east (such as the Khazars) led to the dissolution of Great Bulgaria in the second half of the 7th century. One Bulgar tribe migrated to the confluence of the Volga and Kama Rivers in what is now the Russian Federation (see Volga Bulgaria). Most of them converted to Islam in the beginning in the 8th century and maintained an independent state until the 13th century, others, like the present-day Chuvash, converted to Christianity. Smaller Bulgar tribes seceded in Pannonia and in Italy, northwest of Naples, while other Bulgars sought refuge with the Lombards. Another group of Bulgars remained in the land north of the Black and the Azov Seas. They were, however, soon subdued by the Khazars. These Bulgars converted to Judaism in the 9th century, along with the Khazars, and were eventually assimilated.
Yet another Bulgar tribe, led by Khan Asparuh, moved westward, occupying today’s southern Bessarabia. After a successful war with Byzantium in 680 AD, Asparuh’s khanate conquered Moesia and Dobrudja and was recognised as an independent state under the subsequent treaty signed with the Byzantine Empire in 681 AD. The same year is usually regarded as the year of the establishment of present-day Bulgaria.
Another opinion is that Great Bulgaria, although it suffered a major territory loss from the Khazars, managed to defeat them in the early 70s of the 7th century. Khan Asparuh, the successor of Khan Kubrat, conquered Moesia and Dobrudja after a war with Byzantine Empire in 680 AD. This war ended with signing a peace treaty in 681. Therefore the year of establishment of present-day Bulgaria has to be considered 632, and not 681 AD.