The legacy of the Byzantine emperor Justinian is closely tied to his codification of Roman law. Justinian became emperor at a time of great social unrest and civil disorder in the early history of the Eastern Roman Empire. He was able to defeat the insurrections against his empire but realized that changes needed to be made if the empire was to endure. His solution was to create a unified code of law to be followed in the empire. His Body of Civil Law, which today is known as the Justinian Code, achieved this goal.

The Justinian Code is one of the clearest and most comprehensive edicts ever established. It created a sense of unity and reduced confusion in government. Essentially, it eased internal tensions that had existed in the Byzantine Empire. Justinian was able to create a very organized and efficient bureaucracy because of the code. This allowed the empire to survive for many centuries. Because of the success of the Justinian Code, Constantinople was rebuilt and great works of architecture and engineering were witnessed (Hagia Sophia as an example.) The Justinian Code would be a model of future legal systems in Europe and was important in spreading Roman law.