Ancient Rus. From Rurik to Batu

The book is dedicated to one of the most discussed and controversial periods of our history - the Ancient Russian state, from the founding of Kievan Rus to the Mongol-Tatar invasion. Is it true that the ancient Rus were friends with the Vikings, and that the name of the tribe "Rus" originated from the Iranian language?
Who made Kiev the mother of Russian cities, and what was the actual size of Batu's Mongol army? Read about this and much more in the book by Klim Zhukov, a Russian military historian, medievalist, historical reenactor, and publicist, - "Ancient Rus: from Kiev to Batu".