Part of Kiev-Rus that later became Russia, Belarus and Ukraine. When Russians try to explain this to westerners they usually compare it to the empire of the Franks (Francia/Frankia) that subsequently...
added: bulgarian rus (tow-head), сzech rusy (light), slovensky rus (red), latin russus (red)
The name has occurred from Varangians rus, called by the Novgorod Slavs in 862 year as a military team....