Новгородская первая летопись
The "Primary Chronicle"'s brief account of Oleg's life contrasts with other early sources, specifically the Novgorod First Chronicle, which states that Oleg was not related to Rurik, and was rather a Scandinavian client-prince who served as Igor's army commander. The Novgorod First Chronicle does not give the date of the commencement of Oleg's reign, but dates his death to 922 rather than 912.