The Mongols were well after the vikings. The Kievan Rus came from Viking nobility ruling Slavic population, which lasted for a few centuries and then disintegra

The Mongols were well after the vikings. The Kievan Rus came from Viking nobility ruling Slavic population, which lasted for a few centuries and then disintegrated when the Mongols invaded. Muscovy became the center of Russian vassalage under the Mongols, and after the Mongol empire disintegrated, Muscovy started conquering/uniting the various Russian states under their rule.