Codex Iustinianus

The Codex Justinianus (Latin for "The Code of Justinian") is one part of the Corpus Juris Civilis, the codification of Roman law ordered early in the 6th century AD by Justinian I, who was an Eastern Roman (Byzantine) emperor in Constantinople. Two other units, the Digest and the Institutes, were created during his reign. The fourth part, the Novellae Constitutiones (New Constitutions, or Novels), was compiled unofficially after his death but is now thought of as part of the Corpus Juris Civilis.

Shortly after Justinian became emperor in 526, he decided the empire's legal system needed repair. There existed three codices of imperial laws and other individual laws, many of which conflicted or were out of date. The Codex Gregorianus and the Codex Hermogenianus were unofficial compilations. (The term "Codex" refers to the physical aspect of the works, being in book form, rather than on papyrus rolls. The transition to the codex occurred around AD 300.) The Codex Theodosianus was an official compilation ordered by Theodosius II. In February 528, Justinian promulgated the Constitutio Hac quae necessario, by which was created a ten-man commission to review these earlier compilations as well as individual laws, eliminate everything unnecessary or obsolete, make changes as it saw fit, and create a single compilation of imperial laws in force. The commission was headed by the praetorian prefect, John of Cappadocia and also included Tribonian, who was later to head the other Corpus Juris Civilis projects.

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