First Corpus Juris Civilis, a fundamental work in jurisprudence, is issued by Eastern Roman Emperor Justinian I.

The Corpus Juris Civilis is the modern name for a collection of fundamental works in jurisprudence, enacted from 529 to 534 by order of Byzantine Emperor Justinian I. It is also sometimes referred to metonymically after one of its parts, the Code of Justinian.

Jurisprudence, also known as theory of law or philosophy of law, is the examination in a general perspective of what law is and what it ought to be. It investigates issues such as the definition of law; legal validity; legal norms and values; and the relationship between law and other fields of study, including economics, ethics, history, sociology, and political philosophy.

The foundation of Constantinople in 330 AD marks the conventional start of the Eastern Roman Empire, which fell to the Ottoman Empire in 1453 AD. Only the emperors who were recognized as legitimate rulers and exercised sovereign authority are included, to the exclusion of junior co-emperors who never attained the status of sole or senior ruler, as well as of the various usurpers or rebels who claimed the imperial title.

Justinian I, also known as Justinian the Great, was Byzantine Roman emperor from 527 to 565.

April 7 is the 97th day of the year in the Gregorian calendar; 268 days remain until the end of the year.