While the Western Roman Empire started to disintegrate in the first half of the 5th century AD, the Eastern Roman Empire was still intact and flourishing. Eastern armies guarded the frontier from the Danube to the border with the Sassanid empire. The main Christian centers of the late Roman world were situated in the east, in Constantinople, Antioch and Alexandria of Egypt.
Into this world was born Flavius Petrus Sabbatius Iustinianus, known to posterity as Emperor Justinian I. When Justinian ascended to the throne of Constantinople in 527 AD, he envisioned a plan for the reconquest of the old Western Empire. In order to launch this great invasion, he first however needed a general and an army. The general he ultimately selected to lead this campaign was Flavius Belisarius, a Thracian with a keen strategic and tactical mind as well as experience gained through conflict with the Sassanids. The army was duly formed after signing a peace treaty with the Sassanid Empire.
In 533 AD, Belisarius’ army landed in North Africa, a rich Roman province controlled by the Vandals, a Germanic people who had migrated there during the last years of the Western Roman empire. Belisarius acted swiftly and effectively, defeating the Vandals, led by King Gelimer. The conquest of North Africa was made easier by the religious divisions between the Romans and the Vandals, as the Vandals were Arian Christians while the Romans were Nicene Christians. The Vandals had also encountered difficulties in integrating with the local Roman elites.
After the conquest of North Africa, the next step in Justinian’s plan was to recover the Ostrogothic kingdom of Italy, founded by Amal king Theodoric the Great. In the Ostrogothic kingdom, relationships between the old Roman elites and the recent Gothic arrivals had plummeted. After the death of Theodoric, power had passed to his daughter Amalasunta, who was deeply pro-Roman and fascinated by Greek and Roman culture. When Amalasunta was imprisoned and disposed of by Theodahad, count of Tuscany, Justinian declared war on the Goths. Belisarius was swiftly sent to Sicily in 535 AD, where he occupied the island with little resistance, before crossing into mainland Italy in 536 AD, where he captured Naples and Rome.
The recapture of Rome had a powerful symbolic meaning although real power was now located in the east. After defending Rome from a Gothic onslot, in 540 AD Belisarius took the city of Ravenna, the old western imperial capital. After having refused the Ostrogothic offer of getting crowned as Emperor of the Western Empire, Belisarius was sent back to the east by Justinian, to deal with the renewed Sassanid threat and probably because of the emperor’s envy of his military prowess. The Ostrogoths under king Totila exploited the absence of Belisarius to mount a counteroffensive that while initially successful, ultimately failed. Justinian’s dreams of reconquering Western Rome was fulfilled at great cost.
The “Gothic wars” caused institutional damage, farmland devastation and civilian casualties in the Italian peninsula. The wars also overstretched the Eastern Roman army and their supply lines. Eastern Rome had few soldiers to spare and it needed most of the legions at the frontier. Belisarius’ expedition had weakened the frontier and the troops which remained were not enough to hold the whole Italian peninsula and North Africa. This situation was exploited by the Lombards, a Germanic people who waged a violent war against the remaining Eastern Roman troops in Italy. The Lombards conquered most of the Italian peninsula except for a few coastal areas. Both Ravenna and Rome remained under Eastern control as they were supplied by the powerful Eastern Roman navy. The segments of Italy controlled by Eastern Rome would remain under the command of the exarch of Ravenna, a military commander subordinate to the emperor. The territories acquired in North Africa were governed by an exarch based in Cathage. These territories were always on the defensive as Constantinople could not supply enough military resources to mount a counteroffensive. The bishop of Rome gradually detached himself from the control and influence of Constantinople. While initially seeking help from Constantinople to defend Rome against the Lombards, the pope eventually found a new defender in the king of the Franks.
In the end, we can say that the Eastern Roman empire under Justinian did not have sufficient manpower or resources to maintain control over the new conquered lands. Although we have little information about the Eastern Roman army of the time, we know that the core of the army was made of Scutati or Scutatoi (shield bearers), which were essentially late Roman legionnaires, equipped with oval shields, Spathas, mail armor and ridge helemts. The role of the cavalry was increased as mobility was more valued on the battlefield. Most cavalry regiments were provided by Germanic peoples, the Huns, the Alans or the Sarmatians, all horse breeding peoples. However, the elite arm of Belisarius’ army was made of Bucellarii, privately owned soldiers who were loyal to their commander. They were the best trained as well as the best equipped of Belisarius’ troops. Belisarius could afford to employ thousands of them. It is also probable that some Limitanei regiments served under Belisarius in North Africa and Italy. Most of the information relating to Belisarius’ campaign comes from Procopius of Caesarea, Belisarius’ personal attendant and secretary.