The Turkut empire disintegrated after 100 years of existence, torn apart by internecine civil wars; and new kingdoms — the Khazar and the Bulgar — arose on its ruins in eastern Europe. The fierce struggle of these two states very soon ended in the expulsion of the Bulgars beyond the Danube, and the rise of the powerful Khazar empire, extending its power over the southern part of eastern Europe. At the head of the Khazar state stood an old Turkut dynasty, and the Khazars, who nomadised in the eastern coastal lands of the Caspian between the courses of the Volga and the Terek, constituted the core of the state. The nearest neighbours of the Khazars were the Bulgars of the Kuban river valley and the Sabirs of northern Dagestan who were under the Khazar supremacy. The Sabirs are also known as Huns. They were beginning to profess Christianity, while Jews penetrated into Khazaria from Iran.
The Khazar state at the point of its flourishing checked the advance of nomad hordes from Asia creating conditions for colonization not only of the wooded steppe belt, but also, partially, of the steppes themselves. In the VIIIth century, the process of settled cultivation in the steppes, closely connected with intensive social and economic differentiation, takes place among some of the nomad tribes. In the country of the Don and the Donets, in northern Caucasus, and in eastern Crimea appear many agricultural settlements and castles protected by stone walls. Trades begin to develop, old towns on the shores of the Black Sea come back to life and new ones spring up in northern Caucasus and the lower Volga. Khazaria was the first feudal state in eastern Europe, which ranged together with the Byzantine Empire and the Arab Caliphate. It boldly interfered in the international affairs of its time and laid claim to the territories of eastern Transcaucasia. In Transcaucasia the Khazars met another aggressive nation — the Arabs, and a close alliance was formed between Byzantium and Khazaria in face of the common enemy. It was only due to the powerful Khazar attacks, diverting the tide of the Arab armies to the Caucasus, that Byzantium withstood against them. Inspite of the fact that as a result of a continuous war, lasting for three decades, and apparently terminating in a glorious victory of the Arabs over the Khazars — their Khagan being forced to turn Muslim in 737 — the Khazars exhausted the resources of the Arabs made them stop in the Caucasus, and checked their further progress into Eastern Europe. The Arabs were forced to send a request for terms seeking an alliance with the Khazars, while the tribes of Transcaucasia looked hopefully to Khazar assistance in their struggle for independence.
Byzantium appreciated friendly relations with the Khazars and tried to strengthen the alliance by all means, intermarriages of the ruling dynasties including. In the 80s of the VIIIth century Byzantium did not support the Goth uprising in the Crimea against the Khazars, though it tried to strengthen its own influence in Khazaria by means of uniting the Khazar Christians into a dependent religious body, the so-called Gothic Eparchy, controled by Byzantium.
The conversion of the Khazar Khagan and his attendants to Judaism thus promoting Judaism to a position of state religion is a phenomenon unprecedented in the history of the Middle Ages. Judaism had been adopted by a Khazar prince in northern Dagestan as early as the 30s of the VIIIth century, but the fact didn't affect the inner life of the Khazar kingdom, and the Khazar population continued to enjoy full liberty of religion for all professing Christianity, Islam or even worshipping their old Turkic god Tengri-khan. At the openning of the IXth century, however, the Jewish Khazars grew in importance at the Khazar's court, seized power and instituted the double kingship, reducing the Khagan, the descendant of the Turkut dynasty, to a position of a sacred king set aside from state power. A political and religious coup d'etat carried through by Obadiah, founder of the Jewish Khazar king dynasty, was followed by religious persecution of Christians and Muslims resulting, in particular, in the abolition of the Gothic Province church unity of the Christian Khazars rather numerous in the Crimea and northern Caucasus. An uprising against the usurper, followed by a long civil war in Khazaria, brought about its decline, and opened the way to the Madyars (Hungarians) into Europe; then came the Pechenegs, who appeared for the first time on the stage of history.