grand prince of Kiev and presumably the son of Rurik, prince of Novgorod, who is considered the founder of the dynasty that ruled Kievan Rus and, later, Muscovy until 1598. Igor, successor to the great warrior and diplomat Oleg (reigned c. 879–912), assumed the throne of Kiev in 912.

Depicted as a greedy, rapacious, and unsuccessful prince by the 12th-century The Russian Primary Chronicle (Russian Primary Chronicle, The), Igor in 913–914 led an expedition into Transcaucasia that ended in total disaster for his forces. He also conducted two expeditions against Byzantium (941 and 944), but many of his ships were destroyed by “Greek fire,” and the treaty that he finally concluded in 944 was less advantageous to Kiev than the one obtained by Oleg in 911. Igor did manage to extend the authority of Kiev over the Pechenegs, a Turkic people inhabiting the steppes north of the Black Sea, as well as over the East Slavic tribe of Drevlyane. When he went to Dereva (the land of the Drevlyane located in the region of the Pripet River) to collect tribute (945), however, his attempt to extort more than the customary amount provoked the Drevlyane into rebelling and killing him.