Byzantine emperors organized and preserved Roman law, making a lasting contribution to the medieval and modern worlds. Roman law had developed from many sources — decisions by judges, edicts of emperors, legislation passed by the Senate, and opinions of jurists expert in the theory and practice of law. By the fourth century Roman law had become a huge, bewildering mass. Its sheer bulk made it almost unusable.

Sweeping and systematic codification took place under the emperor Justinian. He appointed a committee of eminent jurists to sort through and organize the laws. The result was the Corpus Juris Civilis (Body of Civil Law), a multipart collection of laws and legal commentary issued from 529 to 534 that is often simply termed Justinian’s Code. The first part of this work, the Codex, brought together all the existing imperial laws into a coherent whole, eliminated outmoded laws and contradictions, and clarified the law itself. The second part of Justinian’s compilation, the Digest, is a collection of the opinions of the foremost Roman jurists on complex legal problems. The third part, the Institutes, is a handbook of civil law designed for students and beginning jurists. All three parts were given the force of law and formed the backbone of Byzantine jurisprudence from that point on. (See “Viewpoints 8.1: Freeing Slaves in Justinian’s Code and the Qur’an.”) Like so much of classical culture, Justinian’s Code was lost in western Europe with the end of the Roman Empire, but it was rediscovered in the eleventh century and came to form the foundation of law for nearly every modern European nation.