Byzantine Empire /
Full name: Flavius Justinianus
Original name: Petrus Sabbatius
The main achievements of his period was the extension of the empire into the western territories lost to invasions from northern Europe.
He conquered the Vandal territory in North Africa, corresponding to Tunisia and the coasts of Algeria and western Libya; part of modern Morocco; southeastern Spain; all islands of western Mediterranean Sea; and Italy. This "united" empire would surive Justinian's death only with a few years.
On one front, Justinian was unsuccessful, in preventing peoples invading from north of the Danube River to settle inside the empire. Both the Slavs and Bulgars managed to establish themselves permanently.
Being able to establish a period of stability and growth, Justinian saw the need to reform the empire's law system. A team of jurists, under the leadership of Trebonianus worked for years to collect existing Roman law and systemize it. To this were added a new section of laws, and it was promulgated in 534 as the Corpus Juris Civilis, also called Justinian Code. This law system would had great impact on law systems of Europe, even in modern times; it has also had great impact on the development of Muslim law, Sharia.
Justinian also reformed the civil and military administration to fight corruption. He forbid sale of provincial governorships, and developed administrative structures to improve juridical security for most inhabitants. The provincial system was reformed, and in several cases, civil and military authority were combined.
Among the challenges of Justinian was both to collect enough taxes from regions destroyed by bad administration and/or years of warfare, yet prevent abusive taxation on the citizens. His reign saw something as unusual as famous finance ministers, John of Cappadocia and Peter Barsymes
He is also noted for his great building projects of Constantinople and around the empire. He is principally remembered for his two lavish churches, the Hagia Sophia and the SS. Sergius and Bacchus, both in Constantinople. The first represents one of the ancient world's greatest engineering achievements, proving that even medieval Europe could produce great advances. The empire of Justinian was also involved in the building of several aqueducts and bridges, the rebuilding of whole cities devastated by the many earthquakes of this period, fortifications and defenses along the extensive frontiers.
Even in the fields of literature, poetry and philosophy, the reign of Justinian produced noteworthy achievements.
Also for Justinian, theological questions in Christianity was of much importance. His time was the conflict over the nature of Christ, where the schism was between the declared coexistence of divine and human natures as defined at the Council of Chalcedon, and the Monophysite idea of Christ's divine nature. In dealing with this controversial issue, Justinian convened the Council of Constantinople in 553. This proved futile, the conclusions were as harsh as preceding controversy; the Catholic view was reaffirmed and the Monophysite writings were clearly condemned. However, in his attempt to reconciliate, Justinian had caused much anger on both sides, causing a schism between Rome and Constantinople that would last until 610.
Justinian continued a policy of suppressing specific non-Christian groups, including the Montanists. Traditional Roman religions, deviating Christians, and Samaritans were forbidden to teach in any form or way. In many ways, Justinian can be said to be man to end Ancient Egyptian religion, as he abolished the worship of Isis at Philae, and also the worship of Amon at Augila (modern Awjilah, northeastern Libya). He was extremely harsh on the Manicheans, who in many cases paid with their lives for their faith.
For Justinian, his wife, Theodora, would exercise much influence on the politics of the empire. Theodora was a very intelligent woman and a very important partner, and her example would be followed by later emperors.
The Eastern Orthodox Churches have made Justinian a saint, a reflection of the importance he had on the development of early Christianity.
Ethnically he was Illyrian, and spoke Latin. Justinian had no children.