In the middle of the 6th century AD the Bulgarian tribes living between the Caucasus, the Black and Caspian seas were conquered and fell under the rule of the so-called Turkic khanate.

In 632 AD Kubrat, leader of one of the tribes, shook off the power of the Turkut khagan and declared himself an independent ruler. All Bulgarian tribes living in these region immediately united under him. Byzantine chroniclers, contemporaries of those events, referred to the newly founded state as Great Bulgaria.

At the same time the huge Khazar state, established north of Caspian Sea, proclaimed itself a successor to the Turkic khanate and claimed all its former lands including the territory of Great Bulgaria. The Bulgarians were dragged into an arduous and prolonged war.

There is a legend from this period which has come down to us from Byzantine chroniclers. It goes that at his death bed khan Kubrat bid his sons to break a bundle of vine twigs. None of them succeeded. Then Kubrat, himself, took the vine shoots and broke them one by one with his old frail hands. "If you are disunited you will be destroyed one by one as well as these twigs," said the old khan. "Bulgaria will be invincible as long as you will be united against the enemies."

Unfortunately the Kubrat's sons did not follow the father's advice. Each of them, at the head of his troops, fought independently against the enemies. Three years after khan Kubrat's death the capital Phanagoria and the most part of Bulgarian lands were occupied by the Khazars.

Some of the Bulgarian tribes withdrew to the north, where they founded a new Bulgarian state, the so-called Volgo-Kama Bulgaria. This state existed up till the 13th century when it vanished under the smashing blows of the Tatars.

The third Kubrat's son, Asparukh, after desperate defensive battles managed to drive the Khazars back across the Dnepr and to utterly defeat them, thus stopping their offensive westwards. Namely this son was predestined to continue the Kubrat's great deed.