Justinian came to power on August 1st 527 and ruled till 565. Justinian’s rule was the last time the entire empire was unified. Justinian’s wars brought great successes for the imperial image, but also came at a high cost. The entire treasury that Anastasius had saved up had been exhausted, and heavy taxation was needed to pay for the cost of this extensive spending. The conquest only showed victory and progression only upon viewing the map at the end of his reign, which mostly was lost within a few years. All that remained in Byzantine hands till the 7th century is the strip of North Africa regained during the Vandal war.
Justinian believed it was his charge to keep the empire together and regain the territories that had been lost and turn the Mediterranean into a “roman lake.” His duty as a Christian emperor was a duty to re-conquer. This progresses in several phases. In 532, there is the conclusion with an “eternal peace” with Persia, in order to keep territories around him free. Afterwards he turned his attention to the Germanic tribe of the Vandal kingdom in North Africa. The local aristocrats in North Africa called Justinian to assistance because one of the Vandal nobles had deposed and murdered the grandson of the Western emperor Valentinian. Originally he was hesitant, but a bishop told him that it was the will of God. He sent Belisarius out with his troops, along with Procopius. Within a year or two, Belisarius vanquished the Vandal King. Items were brought back such as precious objects that were destroyed in 79 BC by Vespasian. These objects were significant, signaling possession and victory. This war was successful, and resulted in a special coin issue of a medallion with Justinian and Nike/angels. The inscription around it said “Gloria Romanorum” which meant the glory of the Romans.
The campaign in Italy was the Gothic Wars between 535 and 554. Justinian sent troops with Belisarius, but the war went much longer and at a higher cost, and left Italy in a shambles. With Narcisse leading the war, it took another dozen years till finally Italy was subjugated in 552, when the army of the Gothic king was decimated, and the Byzantines took control of Italy. The capital of Byzantine power was in Ravenna.
In 554 for his third campaign, he took on the Conquest of the Visigoths in parts of Southern Spain. This wasn’t a very impressive event, although he was able to gather most of the Mediterranean territory.
The Persian Wars were Justinian’s last campaigns, which Procopius also describes. After the truce that had been declared in 532, eight years later in 540 the Persians broke the peace and attacked the city of Antioch. Justinian sent troops under Belisarius and Narcisse and there was prolonged warfare for 22 years that led to a peace treaty concluded in 562. Byzantine paid 30,000 gold pieces to Persia to keep the peace. One thing that is important is in terms of the religious policy and the responsibility Justinian took on for Christians, which because of this treaty extended the Christian church in the Persian Empire.
Justinian’s desire to create a strong and unified empire also extended to repressing. His repressive measures were quite extensive. In 529 he decreed the closure of the Academy of Athens, one of the great institutions of higher learning, many church fathers had studied there. Was founded by Plato, and had a history that went back 1000 years. The result was that some of the professors from there found refuge in Persia, to the enemy, which is very interesting as it shows how appreciative of classical culture there Persian empire was. In conjunction, Justinian decreed the persecution of ‘Hellenes’, which specifically meant ancient Greeks who weren’t Christians or were pagan. Many nobles had their property confiscated, one committed suicide and several killed. Pagans were arrested and paraded in the city and their books burned. There was a persecution of homosexuals, Justinian ordered them rounded up and their genitals mutilated, the idea of punishing the body part that is part of the crime. Also in 529 there was a restriction of Jewish worship, making them read the Torah in Greek, the Septuagint, rather than Hebrew. Starting with the reign of Justinian there was a curtailment of the civil rights of Jews in the holy land, which was a way of ‘scapegoating’ them in a cultural and political sense.
In positive ways, he did reorganize legal practice. He created the Corpus Iuris Civilis, the body of civil law, and the most lasting effect of his reign. It was in four parts, and still is the basis of Roman law as it is studied in law schools today. The Theodocian code sifted through existing law to eliminate inconsistencies and made the bulk of laws precedents to be used by judges. He commissioned Tribonian to collect a group of 10 lawyers to sift through the laws. Tribonian was a practicing pagan, and was unaffected by Justinian’s persecutions, so it was clear not all the laws were complete. The Codex Justinian, which was different from the Theodocian Code, was the treatment of Christianity. Justinian integrated the church into the empire as well by declaring that all canon law should have the force of secular war, setting secular authorities at the service of enforcement of religious matters.

The Nika Riot was the decisive moment that almost cost Justinian the throne only five years after he came to power. They protested against Tribonian and John the Cappadocian. Justinian assumed his cause was lost, and in trying to ready to flee, his wife Theodora stops him. Belisarius with his troops went into the Hippodrome where the people were assembled, and started a bloody massacre between 30,000 and 50,000. It was a violent moment when the Emperor turned on the population in order to save his throne. In the course of the riot, 1/3 of the inner city was burned down, and that necessitated a huge rebuilding project, which Justinian led.

After the Nika Riot, and after the city was burned, including the original Hagia Sophia that had stood there, Justinian felt the need to reconstruct the church on a grander scale. What makes the building so amazing, it has withstood the test of time, it’s sheer scale, and the pioneering use of a large dome to surmount a central space.

The challenge of the architects was to put a round dome on a square structure. This was something that Justinian’s architects pioneered, the use of of triangular segments inside that allow the joining of the square with the cuppula.

Justinian was also responsible for infrastructure and fortification building, like bridges. And the church of San Vitale in Ravenna was built by him, with art covering it, including the famous mosais of Theodora and Justinian.