East Slavs, according to the first written evidence, stood out from the Indo-European community by the middle of the 2nd century. BC e. By the next millennium, they became very numerous and influential in the world around them. So, references to the Eastern Slavs began to appear among Arab, Roman, Byzantine, Greek authors. Ancient authors called these people “sklavins”, “ants”, “wends”, speaking of them as tribes of “countless”.
During the period of the great migration, the Eastern Slavs began to be squeezed out by other peoples. As a result, Slavic fragmentation began. Part of the people remained in Europe. Later they will be called the southern Slavs. Serbs, Bulgarians, Croats, Montenegrins, Bosnians, Slovenes will come from them. Another part of the people moved to the northern territories. They began to be called Western Slavs. From them came the Poles, Czechs, Slovaks. Western and southern peoples were captured by other peoples.
According to scientists, the rest of the Slavic people did not want to obey anyone. People moved to the East European Plain (to the northeast). Thus, the Eastern Slavs appeared. The origin of Belarusians, Russians and Ukrainians is associated precisely with these immigrants.
It should be noted that many tribes during the resettlement rushed to the ruins of the Roman Empire, to Central Europe. Under the onslaught of the invaders in 476 AD, Rome fell. On its territory, the invading barbarians created their statehood, using the cultural heritage of the Romans.
The Eastern Slavs went to a territory where there was no cultural heritage. One part of the people went to Lake Ilmen. After some time, the ancient city of Novgorod will be founded on this place. The other half of the eastern Slavs went to the lower and middle reaches of the Dnieper. In this place Kiev will be founded.
Already in the 6-8 centuries, the Eastern Slavs settled throughout the East European Plain. However, other peoples lived in the same territory. The Baltic coast and the north were inhabited by the Baltic (Latvians, Lithuanians) and Ugro-Finnish tribes (Estonians, Finns, Ugrians (Hungarians), Mansi, Khanty, Komi). It should be noted that the colonization of the territory was peaceful. Eastern Slavs and their neighbors in this territory got along with each other.
However, the situation in the southeast and east was somewhat different. On that territory, the steppe adjoined the East European plain. Here, the neighbors of the Slavs were the steppe nomads - the Turkic group. At that time, peoples whose lifestyles were very different (sedentary and nomadic) often quarreled with each other. Due to raids on settled tribes, nomads existed. Thus, almost 1000 years of history of the Eastern Slavs consisted in the struggle against nomadic steppe tribes.
The Türks created their statehood on the southeastern and eastern borders of Slavic settlements. In the middle of the 6th century there was an Avar Kaganate - a Turkic state. In 625, Byzantium defeated this state; the Avar Kaganate ceased to exist.
In the 7-8 centuries on the same territory there is another state - the Bulgarian kingdom. Other Turks found it. After a while, this state collapsed. Part of the Bulgars, who went to the middle reaches of the Volga, was formed Volga Bulgaria. Another part of the people moved to the Danube. Here they formed the Danube Bulgaria. Later, the newly arrived Turks merged with the local southern Slavs. Thus, a new ethnic group was formed, taking the name of the immigrants of the Bulgarians.
After the departure of the Bulgars, the steppes were occupied by the Pechenegs (new Turks). On the territory of the lower Volga and the steppes between the Azov and Caspian seas, semi-nomadic Turks created the Khazar Khaganate. The Khazars dominated over the East Slavic tribes , receiving tribute from some tribes up to the 9th century.