When did Roman law begin and how long did it remain in use in the Byzantine Empire?

Roman law originated with the founding of the city of Rome in 753 BCE and continued to evolve throughout the history of the Roman Empire. Its earliest systematic codification, the Law of the Twelve Tables, was traditionally dated to 451–450 BCE.123

In the Eastern, or Byzantine, Empire, Roman law remained in use until 1453. During the 6th century CE, Emperor Justinian I compiled and organized existing legal materials into the Corpus Juris Civilis, which served as the primary legal foundation for the Byzantine world. In the 9th century, Emperor Leo VI the Wise further updated this system with the Basilica, a comprehensive legal code written in Greek that remained the standard for the remainder of the empire's existence.145