The Rus'–Byzantine Treaty, between the Byzantine emperor Constantine VII and Igor I of Kiev, was concluded either in 944 or 945. It was a result of the Rus'-Byzantine War of 941 undertaken by Kievan Rus' against Constantinople. Its provisions were less advantageous for the Rus' than those of the previous treaty, associated with the name of Igor's predecessor Oleg. It was one of the earliest written sources of Old Russian Law.
