In the 6th century the cities of the Balkan peninsula had to deal with several earthquakes and plagues and were disturbed by invading barbarians. In the 5th century the western Empire was already lost to the Vandals, Goths and Burgundians. In the 6th century East was troubled by the Slavs and Avars. In all four cities we see a signs of destruction during this period. The buildings that were destroyed were rebuilt or demolished. New building was rare. The buildings that were newly built were military structures or churches.
The 6th century is characterized by the reign of Justinian. His ambition was to restore the former Empire. The Balkan peninsula played an important role in his plans. The army was amplified and the frontier was fortified more intensely. In the towns in the direct hinterland of the frontiers new defense works were built, sometime using city walls or neglected defense walls to built new fortifications. The provision for the needs of the army continued to be organized through cities during the whole Late Antiquity. At this period military garrisons appear to have been common in cities. Since Diocletian military and administrative power were separated, but Justinian united them in the function of the military commanders to moderate the organization and administration of the army. This resulted in the increasing influence of the local military commanders and by urban garrisons on towns. The cities more and more functioned as centers of military administration. Both Thessaloniki and Corinth were cities where a garrison was placed and they were an important military center. Here we see that fortifications were rebuilt or renewed and other new buildings appeared.
Justinian restored the frontiers and even reconquered some of the territory lost to the western barbarian kings. The urban revival was of short duration. The successors of Justinian were not able to stop the new invasions of the Balkan provinces and concentred on the more eastern parts of the empire. Soon the reconquered parts were lost again. More and more barbarian tribes invaded the Balkans and Greece and settled permanently. These settlements are called sklaviniai and dominated many districts. The indigenous population searched for places of refuge. Inhabited centers contracted and regrouped around a defensible acropolis, called a kastro, or were abandoned in favor for such positions elsewhere. This is the case for Argos, Athens and Corinth. The remaining population of Corinth finally retreated to the fortified height of the Acrocorinth.
In cities of the 6th century that were not controlled by a military leader, administration was given from the hands of the imperial officials into that of the Church. The most honorable offices were given to the wealthy elite, that also donated generously to the Church, or to clergy and even monasteries were given duties. The office was more and more localized. This form of government was much difficult to control by agents of the central administration than the
old city councils had been. These changes affected the relations between city and empire. It is likely that many cities enjoyed greater independence on the 6th century. Independence was greater in proportion to a city’s distance from the centers of imperial power. In these cities the Church seems to have emerged as the most important factor in maintaining some form of local government. Because of the Church’s role in the urban organization, Christianity became a city-centered religion. Many Roman cities survived precisely because they were the residence of a bishop, which ensured the urban organization.
In all four cities was the construction of new churches continued even more than before, while pagan temples were ravaged, not repaired and sometimes converted into a Christian church. The larger churches in the 6th century were built by the more high ranked persons, like the emperors and the bishops. Justinian ordered the construction of the Hagia Sophia in Constantinople. These elaborate buildings reflected their power. Also in the smaller cities the greatest expenditure appears to have been invested in the construction and decoration of churches, which occupied the most important sites in the center of the cities and along the principal roads.
A limited number of wealthy families built their houses either along the main streets or in a separate quarter on the periphery of the city. They presumably played their role in the administration of their communities, but seem not to have been anxious to proclaim their status. Only a small number of less wealthy artisans and shopkeepers lived within the fortifications, none are likely to have played an active role in government. The houses of the rich people maintained, but were eventually divided into smaller rooms for multiple dwelling, often with mud brick floors over or instead of the splendid mosaic which are so characteristic of the fine houses. Poorer dwellings or the accommodation of small traders or artisans frequently were built over existing public space, such as the late antique forum or palaestra.
Although cities were smaller and less spectacular to look at and they housed a much nar- rower range of urban activities, it does not mean that we must cease to regard them as cities. They continued to fulfill a large number of functions which can only be seen as urban. Cities remained administrative centers and emperors continued to reside in cities. Imperial officials like provincial governors continued to have their headquarters there, even though there power had diminished. Tax collection was still organized through cities. Cities were still seen as im- portant, as they were garrisoned and the conduct of wars centered on the defense and capture of cities. But they were no longer the classical urban center, functioned as centers of secular administration for an attached rural territory.
Most cities were reduced in size dramatically and the center was confined to a kastro. It seems that the majority of the population was excluded from these fortified enclosures. The church, restricted groups of notables and perhaps the military establishment occupied cities. The city functioned simply as a center for ecclesiastical and military administration. Outside the walls there were sometimes signs of habitations. This suggests that cities were encircled by extramural settlement. People living outside the kastro probably lived in modest dwellings that leave no or little traces.
As said above more and more barbarian tribes invaded the Balkans and Greece and set- tled permanently in sklaviniai and dominated many districts. The Empire claimed a political sovereignty over the whole region, but it was rarely able to make this effective. But in Argos, Athens, Corinth and at the Hexamilion Slavic pottery was found. This indicates that the people living were Slavs themselves or that they were trading with Slavs who settled in the area. The Slavs and the indigenous population lived next to each other without much problems. There were probably many areas in which the indigenous population and the traditional patterns of local social structure and political organization may have survived and where imperial authority may have been recognized.