Answer: Roman law.
Step-by-step explanation:
Roman law is the greatest legacy of Roman civilization. In 528, Emperor Justinian ordered his legal officials to compile a code that would resolve many legal issues. The Codex was published and entered into force in 534. Many fragments of Justin's collection have been preserved to this day. Roman law is still involved today in many legal norms of different countries, and as a regular subject, it is studied in numerous law studies around the world.