International Judicial Monitor
Published by the International Judicial Academy, Washington, D.C., with assistance from the
American Society of International Law

Fall 2016/Winter 2017 Issue

Leading Figures in International Law


Gaius, Roman Jurist

Gaius, Roman Jurist

By: James G. Apple, Editor-in-Chief, International Judicial Monitor

In my wanderings through the library of the University of Edinburg Law School, which I attended several years ago as a graduate student, or maybe it was during a prerusal of offerings in one of the local Edinburgh bookstores, I came across an interesting title. It was Great Jurists of the World. It included essays about the many judges, jurists, legal scholars, legal authors, and legal philosophers down through the ages, beginning in Roman times, who had made the greatest contributions to the development of law and legal systems. I bought a copy of this book and have browsed through it from time to time for information about legal history.

The first essay in Great Jurists of the World is about Gaius, a Roman legal writer.

Gaius could be considered somewhat a ghost in history, because so little is known about him. No one knows what his real name was. The name now given to him is virtually meaningless. Gaius was a common personal (praenomen) name, as opposed to surname or given name. that was adopted by many Roman people. One was a notable figure in Rome, Gaius Julius Caesar. No other name has ever been attached to the Gaius who was the prominent legal scholar.

Other information about Gaius is also not known. No one knows his date and place of birth, where he was born, or how he came to write the influential legal


treatises that are credited to him. What is known about him, from the best of historians research, is that he lived during the years 130 to 180 A.D., during the reigns of the Roman emperors Hadrian, Antonius Pius, Marcus Aurelius, and Commodus.

Although Gaius wrote several individual treatises on Roman law, he is best known for his Institutes, which provide a comprehensive survey of Roman private law. The Institutes are divided into four books, dealing respectively with status of persons and their differences, status of things or inanimate objects and rights relating to them, intestate succession and obligations, and the existence and forms of causes of actions.

Why is Gaius so well regarded when so little is known about him? First, his Institutes were selected by one later Roman emperor, Theodosius II (401-450 A.D.  ) to be included in his Law Code (438 A.D.). Gaius’ writings were also selected by that Emperor to serve as precedent for Roman judges in rendering decisions in specific cases.That status, however, is not the real reason for his historical importance as a “Great Jurist.” The reason is that , some 350 years after his Institutes were written, they were included almost word for word into the Emperor Justinian’s great work, Corpus Juris Civilis (529-533 A.D.) This legal treasure became the basis for almost all of the civil law systems of Europe, South America and other places in the world. It is still used in many of modern legal systems in modern times. Corpus Jurist Civilis, and with it Gaius’ Institutes, also became the basis for the development of international law.

Providing the basis for so many legal systems and as one of the foundations for international law,  makes Gaius worthy of inclusion in Great Jurists of the World.


ASIl & International Judicial AcademyInternational Judicial Monitor
© 2017 – The International Judicial Academy
with assistance from the American Society of International Law.

Editor: James G. Apple.
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