The Names of Peoples
In this book we speak of Russia and the Russians of the tenth to thirteenth centuries, although during this period the three Eastern Slavic peoples, the Ukrainians, Byelorussians and Russians, had not yet formed and were still a single ethnic unit—the Eastern Slavs, the “Rus” or “russkiye”, as they called themselves in the chronicles and all other works, including The Lay of Igor’s Host. The reader should bear in mind that the Russia of the tenth to thirteenth centuries was not yet modern Russia, and the Russians of the same period were the Eastern Slavs as a whole, the ancestors of the modern Russians, Ukrainians and Byelorussians, three fraternal peoples.
Likewise we should bear in mind that the Mongols or Tartars of Old Russian literary works and folklore are not a single ethnic concept. This is the name by which works refer to the conquerors and oppressors of Russia who were united under the rule of Genghis Khan, Batu and later the Golden Horde. They were unions of various tribes, primarily nomadic and semi-nomadic.