Gaius, << GAY uhs, >> was a leading authority on Roman law during ancient times. He lived in the A.D. 100’s and wrote many important legal works. His law student’s textbook, The Institutes, was widely used and had great influence on later legal development. It became the basis, in part, of Emperor Justinian’s Institutes, a textbook for law students and lawyers that formed part of the Justinian Code.
