We know Kiev was a powerful city-state, but who exactly founded it is a subject of debate. Most historians now believe that the settlers of Kiev were Slavic people who migrated from around the Black Sea, but there's an older theory that the settlers of Kiev were actually like Vikings. That theory goes that Vikings came down to Kiev from rivers like the Dnieper and founded a trading outpost similar to ones they founded in Iceland and Greenland. Which is an awesome idea and everything, but Russian, the language that developed from what the Rus spoke, sounds a lot more Slavic than it sounds, you know, Swedish. To illustrate, here is a Swede fighting a Russian over who founded Kiev. Kiev was founded by the Slavic ancestors of Russia. No, of course Kiev was founded by the Swedes.