1530s, from Medieval Latin Russi "the people of Russia," from Rus, the native name of the people and the country (source of Arabic Rus, Medieval Greek Rhos), originally the name of a group of Swedish merchant/warriors who established themselves around Kiev 9c. and founded the original Russian principality; perhaps from Ruotsi, the Finnish name for "Sweden," from Old Norse Roþrslandi, "the land of rowing," old name of Roslagen, where the Finns first encountered the Swedes. This is from Old Norse roðr "steering oar," from Proto-Germanic *rothra- "rudder," from PIE *rot-ro-, from root *ere- "to row."
Derivation from the IE root for "red," in reference to hair color, is considered less likely. Russian city-states were founded and ruled by Vikings and their descendants. The Russian form of the name, Rossiya, appears to be from Byzantine Greek Rhosia. Russification is from 1842.