The Code of Justinian ( Codex Justinianus , Justinianeus or Justiniani ) 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 Eastern Roman 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 also thought of as part of the Corpus Juris Civilis .
From 527, Saint Justinian I, originally Flavius Petrus Sabbatius Justinianus, Byzantine emperor, held the eastern frontier against the Persians; reconquered former Roman territories in Africa, Italy, and Spain; and ruled jointly with Theodora, his wife, to 565.
Belisarius, his general, led campaigns against the Vandals in north and the Ostrogoths.
Saint Theodora, Byzantine empress, ruled jointly with Justinian I, her husband.
Saint Justinian I, traditionally also known as the Great in the Orthodox Church, reigned. During reign, Justinian sought to revive the greatness and the lost historical western half. Justinian constitutes a distinct epoch in the later history, and the ambitious but only partly realized "restoration" marked his reign.
Because of restoration activities, modern historiography sometimes called the "last" Justinian I. The partial recovery of the defunct west expressed this ambition. Belisarius, his general, swiftly eliminated the Vandal kingdom in north. After the kingdom of Ostrogoths for more than half a century, Belisarius, Narses, and other generals subsequently restored Dalmatia and Sicily. Liberius, the prefect, reclaimed the south of the Iberian peninsula and thus established the province. These campaigns again established control over the western Mediterranean and increased the annual revenue over a million solidi. During reign, Justinian also subdued the Tzani, a people on the coast of the Black Sea.
A still more resonant aspect of legacy of Justinian I rewrote the Corpus Juris Civilis, still the basis of uniform civil law in many modern states. His reign also marked a blossoming of culture, and his building program yielded such masterpieces as the church of Hagia Sophia. A devastating outbreak of bubonic plague in the early 540s marked the end of an age of splendor.