The Corpus of Civil Law
For centuries the senate in Rome had been passing laws and ordnances governing the actions of Roman citizens. Roman emperors had also established thousands of decrees and laws. Up until now, these laws were recorded in a variety of scrolls, books, and tablets, which were spread throughout the Roman Empire. This made it very difficult for Romans to understand their laws and rights.
The Byzantines inherited their legal system from the Romans. The Byzantine emperor Justinian hired a commission to review all the laws that had accumulated over the centuries and to simplify them. This commission categorized the laws into classes based on the issues that they dealt with. They combined many similar laws, made complex laws more simple, while getting rid of many outdated laws.
This new system of laws were all recorded in a single book known as the Corpus of Civil Law, or Justinian Code. The Corpus of Civil Law would become the basis for the laws of many western civilizations.