Kievan Rus' law
Kievan Rus' law or law of Kievan Rus', also known as old Russian law or early Russian law, was a legal system in Kievan Rus' (since the 9th century), in later Rus' principalities, and in the Grand Duchy of Lithuania from the 13th century. Its main sources were early Slavic customary law and Zakon Russkiy (Law of Rus'), which was partly recorded in Rus'–Byzantine Treaties.