The barbarian invasions of the Roman Empire brought chaos and destruction to ancient cities. From the Visigoths sacking Rome to the Vandals conquering North Africa, these attacks exposed urban vulnerabilities and disrupted life across the empire. The Eastern Roman Empire also faced invasions, with Slavs, Persians, and Arabs threatening major cities.

As the Western Empire collapsed, political instability further challenged urban centers. Germanic kingdoms emerged, creating a patchwork of competing states. The Byzantine Empire tried but failed to restore unity. Cities had to adapt, becoming more autonomous and developing new forms of governance as imperial authority faded away.

Barbarian Invasions of Ancient Cities

Major Barbarian Attacks on Roman Cities

• The Visigoth sack of Rome in 410 CE exposed the vulnerability of even the greatest Roman cities to barbarian attacks and sent shockwaves throughout the empire
• Attila the Hun invaded Gaul in the 450s CE and sacked several major Roman cities (Metz, Reims), spreading fear and devastation
• The Vandals invaded North Africa in the 420s-430s CE, conquering key cities (Carthage) and disrupting the critical grain supply to Rome
• Anglo-Saxon invasions of Britain in the 400s-500s CE led to the fall of Roman cities and towns (Londinium, Verulamium) as urban life declined

Invasions of the Eastern Roman Empire

• Slavic and Avar invasions in the Balkans in the 500s-600s CE destroyed many Roman cities in the region (Sirmium, Singidunum)
• The Sassanid Persians captured the major Byzantine city of Antioch in 540 CE in the wars of Justinian's reign
• The Arab Islamic conquests of the 600s CE seized important eastern cities from the Byzantines (Damascus, Jerusalem, Alexandria)
• The Bulgars invaded Byzantine Thrace in the 600s-800s CE, threatening Constantinople and destroying several cities (Adrianople)

Political Instability After Roman Collapse

Fragmentation of the Western Roman Empire

• The deposition of the last Western Roman emperor Romulus Augustulus in 476 CE by Odoacer marked the formal end of the Western Empire and left Italy politically fragmented
• Germanic kingdoms emerged in former Western Roman provinces like the Visigoths in Hispania, Franks in Gaul, and Ostrogoths in Italy, creating a patchwork of competing states
• The Western Empire broke up into various rival barbarian kingdoms (Burgundians, Alemanni, Vandals, Suebi) that frequently fought each other
• Some isolated regions like Soissons, Dalmatia and Britannia maintained Roman rule for a time before eventually falling to invaders

Eastern Roman (Byzantine) Attempts to Restore Unity

• The Eastern Roman (Byzantine) Empire tried to reassert control over some lost western territories in the 500s CE under Justinian I but failed to fully restore political unity
• The Byzantines managed to reconquer some parts of Italy, North Africa and southern Spain but these gains proved temporary and unsustainable
• The devastating Plague of Justinian in the 540s CE weakened the Byzantine army and tax base, forcing them to abandon most of these ambitious western reconquests
• The Byzantines were further distracted by wars with Persia and then the rise of Islam, leaving them unable to effectively project power in the West

Consequences for Urban Autonomy and Governance

• Many cities became semi-autonomous as centralized Roman authority faded, having to fend for themselves and make their own political arrangements
• Some cities voluntarily submitted to barbarian rulers in exchange for protection, while others tried to maintain independence
• Bishops and local elites increasingly took over the administration and defense of cities as imperial institutions broke down
• Cities experimented with new forms of government like popularly elected officials, citizen assemblies, and power-sharing between secular and religious authorities

Consequences of Barbarian Invasions

Damage to Urban Infrastructure

• Successive waves of invasions damaged or destroyed key infrastructure like aqueducts, walls, public buildings and roads in many cities that went unrepaired
• The loss of security and damage to trade networks caused steep urban population decline in most former Roman cities in the 400s-600s CE
• Aqueducts were a frequent target of invaders, depriving cities of fresh water and sanitation when they were cut
• Monumental public buildings (amphitheaters, baths, temples, basilicas) fell into disrepair or were cannibalized for building materials

Depopulation and Abandonment of Cities

• Some cities like Rome itself lost up to 90% of their peak Roman population due to deaths, captives taken, and refugees fleeing
• Declining populations and tax revenues made it hard to maintain urban services, leading to decay and partial abandonment of many cities
• Large areas within city walls became uninhabited with abandoned buildings, overgrown vegetation and even farms and pastureland
• Cities shrank and became more ruralized, with smaller, poorer populations living amidst the ruins of their former glory

Decline in Quality of Urban Life

• The quality of urban life declined with loss of amenities, deteriorating sanitation and living standards for remaining residents
• Many cities lost access to clean aqueduct water, leading to unsanitary conditions and disease
• Urban services like public baths, latrines, sewers, street cleaning and trash collection fell into disrepair
• The decline of long-distance trade reduced access to imported goods and luxuries that had enriched urban life
• Cities became more self-sufficient and focused on basic needs rather than the lavish public spaces and entertainments of the Roman era

Urban Responses to Invasions

Fortification and Defensive Measures

• Many cities built or strengthened defensive walls, becoming more inward-looking and fortified
• Some cities reduced their defended area, with smaller perimeters enclosing only the core as suburbs were abandoned
• Amphitheaters, temples and other solid stone buildings were converted into fortresses
• City walls were hastily repaired with rubble and spolia (repurposed stone) from abandoned buildings
• Some cities built walls for the first time, like Constantinople's massive Theodosian Walls built in the early 400s CE

Militarization of City Governments

• Urban governments became more militarized, diverting resources to defense and maintaining armed forces
• City officials took on military roles and titles as defense became the top priority
• Local elites raised private armies or militias to defend their cities in the absence of imperial troops
• Some cities came to arrangements with barbarian rulers, receiving protection in exchange for tribute or submission
• Cities in frontier areas became more like armed camps than civilian settlements

Adaptation and Self-Reliance

• Self-reliance and providing for defense became a key priority as cities could no longer count on imperial armies for security
• Local food production within and around cities became critical as long-distance trade broke down
• Cities stockpiled food and supplies to withstand sieges, with granaries and storehouses
• Some cities maintained a level of self-governance and civil society through the efforts of local elites and the church
• Cities that adapted and found effective defensive and economic arrangements had a better chance of surviving the upheavals of the era