Eastern Southeast Europe (100–243 CE): Roman Dacia, Imperial Prosperity, and the Danube Frontier

Settlement and Migration Patterns

The Conquest and Organization of Roman Dacia

Between 100 and 243 CE, Eastern Southeast Europe reached the height of Roman political and administrative integration. The defining event of the age was Emperor Trajan's conquest of the Dacian Kingdom following the Dacian Wars of 101–102 and 105–106 CE. After the defeat of King Decebalus, Rome organized the new province of Dacia with its capital at Ulpia Traiana Sarmizegetusa, attracting settlers from throughout the empire, including Italy, the Balkans, Gaul, Hispania, Syria, and Asia Minor.

South of the Danube, the provinces of Moesia and Thrace continued expanding under stable imperial administration, while long-established Greek cities such as Byzantium, Tomis, Callatis, Odessos, Mesambria, and Apollonia remained prosperous commercial and administrative centers.

Urban Growth and Frontier Stability

Roman administration encouraged sustained urban expansion throughout the region. Provincial capitals, military colonies, mining settlements, and market towns expanded through planned street systems, public buildings, baths, forums, amphitheaters, and defensive works. The Lower Danube became one of the Roman Empire's principal military frontiers, protected by legionary fortresses, auxiliary camps, roads, bridges, and river patrols.

Although generally prosperous, the frontier experienced increasing pressure during the later decades of the period as northern peoples, including early Gothic groups, began appearing more frequently beyond the imperial frontier.

Economic and Technological Developments

Imperial Prosperity and Regional Commerce

Roman Dacia became one of the empire's richest frontier provinces. Gold and silver mines in the Apuseni Mountains, together with agricultural production throughout the Danube basin, generated enormous wealth for both provincial society and the imperial treasury.

The Lower Danube connected extensive commercial networks linking Central Europe, the Black Sea, the Balkans, and the eastern Mediterranean. Grain, wine, livestock, timber, salt, fish, metals, ceramics, textiles, glassware, and luxury goods circulated through an increasingly integrated provincial economy.

Roman Engineering and Infrastructure

Roman engineering transformed the region. Roads, bridges, aqueducts, harbors, military camps, and fortified frontiers expanded throughout Dacia, Moesia, and Thrace. Imperial investment maintained transportation corridors linking provincial capitals, mining districts, military installations, and Black Sea ports.

Iron technology continued supporting agricultural expansion, while hydraulic engineering, quarrying, surveying, and mining techniques reached unprecedented levels of sophistication throughout the frontier provinces.

Cultural and Artistic Developments

Roman Provincial Culture

The second century represented the height of Roman provincial civilization in Eastern Southeast Europe. Public architecture, sculpture, mosaics, frescoes, inscriptions, baths, theaters, and temples flourished throughout the urban centers, blending Roman civic traditions with enduring Hellenistic influences inherited from the earlier Greek colonies.

Latin became increasingly important in administration, law, and military life, while Greek remained dominant within many coastal communities and commercial networks.

Indigenous Cultural Continuity

Despite extensive Romanization, indigenous traditions remained remarkably resilient. Thracian and Dacian artistic practices continued through metalworking, pottery, jewelry, funerary monuments, and equestrian equipment. Local elites increasingly adopted Roman citizenship, dress, language, and architecture while preserving important elements of regional identity and religious practice.

Social and Religious Developments

Provincial Society and Imperial Administration

Roman provincial government reached its fullest development during this age. Municipal councils, governors, military commanders, and provincial elites cooperated in administering prosperous frontier provinces whose economic importance steadily increased.

Veterans settled throughout the region, contributing to demographic diversity while strengthening Roman authority and frontier security.

Religious Diversity and the Spread of Christianity

Religious life remained extraordinarily diverse. Traditional Thracian and Dacian beliefs continued alongside Roman and Greek cults, while the imperial cult became an important feature of civic identity. Eastern mystery religions, including the cult of Mithras, spread widely among soldiers, merchants, and urban populations.

Christian communities gradually appeared in many of the larger cities during the second and early third centuries. Although still a minority religion, Christianity became an increasingly visible component of the religious landscape, foreshadowing the profound transformations of Late Antiquity.

Long-Term Consequences and Historical Significance

Between 100 and 243 CE, Eastern Southeast Europe experienced the greatest extent of Roman political authority in its history. The conquest of Dacia secured one of the empire's richest mining regions while extending Roman administration beyond the Danube for the first time. Prosperous provincial cities, extensive infrastructure, thriving commerce, and cultural integration transformed the region into one of the Roman world's most successful frontier systems.

By the close of the period, however, increasing military pressure along the Danube hinted that this prosperity would not endure indefinitely. The frontier established under Trajan and his successors would soon face the mounting challenges that defined the Crisis of the Third Century and the beginning of Late Antiquity.

Trajan launches his first campaign in 101, and forces Decebalus to sue for peace.

Within a few years, however, Decebalus breaks the treaty, and in 105 Trajan begins a second campaign.

This time, the Roman legions penetrate to the heart of Transylvania and storm the Getian capital, Sarmizegetusa (present-day Grădiștea de Munt); Decebalus and his officers commit suicide by drinking hemlock before the Romans can capture them.

Rome memorializes the victory by raising Trajan's Column, whose bas-reliefs show scenes of the triumph.

A Dacian ethnic group will arise over the next two hundred years as Roman colonists commingle with the Getae and the coastal Greeks.

Literacy spreads, and Getae who enlist in the Roman army learn Latin.

Gradually a Vulgar Latin tongue supersedes the Thracian language in commerce and administration and becomes the foundation of modern Romanian.

A religious fusion also occurs.

Even before the Roman invasion, some Getae worship Mithras, the ancient Persian god of light popular in the Roman legions.

As Roman colonization progresses, worshipers faithful to Jupiter, Diana, Venus, and other gods and goddesses of the Roman pantheon multiply.

The Dacians, however, retain the Getian custom of cremation, though now, amid the ashes they sometimes leave a coin for Charon, the mythological ferryman of the dead.

From the newly conquered land, Trajan organizes the Roman province of Dacia, whose capital, Ulpia Trajana, stands on the site of Sarmizegetusa.

Many Getae resists Roman authority and some flee northward, away from the centers of Roman rule.

Trajan counters local insurrection and foreign threat by stationing two legions and a number of auxiliary troops in Dacia and by colonizing the province with legionnaires, peasants, merchants, artisans, and officials from lands as far off as Gaul, Spain, and Syria.

Agriculture and commerce flourish, and the Romans build cities, fortresses, and roads that stretch eastward into Scythia.

Emperor Trajan employs Apollodorus in Dacia to build a bridge across the Danube (pictured on Trajan's Column).

Its twenty stone masonry piers—one hundred and fifty feet (forty-five meters) high, sixty feet (eighteen meters) wide, and one hundred and seventy feet (fifty-two meters) apart—support the span’s wooden superstructure.

The Middle East: 100–111 CE

Trajan’s Ambitious Eastern Expansion

The opening years of the second century CE see Roman Emperor Trajan decisively completing his conquest of Dacia, modern-day Romania, significantly enriching the Roman treasury with gold and silver from its mines. His attention then shifts decisively eastward, toward the persistent rivalry with the Parthian Empire. Trajan’s ambitions, reflecting Rome’s strategic interest in securing critical eastern trade routes and stabilizing its frontier, lead to an aggressive military posture against Parthia, marking one of the most significant chapters in Roman expansion into the Middle East.

The Roman frontier in the East, largely governed through indirect means—particularly via client kingdoms and allied states—has long buffered direct conflict with Parthia. However, Trajan's policy signals a more direct and confrontational approach, and his preparations foreshadow the extensive campaign to come. Rome seeks not just territorial expansion but to curb Parthian influence decisively, thereby securing lasting dominance over key areas such as Armenia, a strategically valuable region continually contested by the two great powers.

During this era, both empires experience internal complexities. The Parthian Empire, under Pacorus II and later Osroes I, contends with internal dissensions and regional aristocratic autonomy, factors that Trajan intends to exploit in his forthcoming eastern campaigns. Meanwhile, Roman provinces in the Middle East—particularly Syria, with cities like Antioch serving as crucial logistical and administrative hubs—are steadily strengthened to support Trajan’s eastern ambitions.

Thus, the years 100–111 CE lay the groundwork for what will soon become one of Rome's boldest imperial adventures, setting the stage for dramatic shifts in the geopolitical landscape of the Middle East.

The Romans reorganize Dacia as a Roman province and build another capital at a distance of forty kilometers from the old Sarmizegetuza, naming it Colonia Ulpia Traiana Dacica Augusta Sarmizegetuza.

The province includes the modern Romanian regions of Transylvania, Banat and Oltenia, and temporarily Muntenia and southern Moldova, but not the nearby regions of Moesia.

A large part of the population has been either exterminated or fled to regions north of the Carpathians.

As a consequence of this depopulation, Roman colonists are brought in to cultivate the land and work the gold mines alongside the remaining Dacians.

Besides the Roman troops, these are mainly first- or second-generation Roman colonists from Noricum or Pannonia, later to be supplemented with colonists from other provinces: South Thracians (from the provinces of Moesia or Thrace) and settlers from the Roman provinces of Asia Minor.

Roman influence is broadened by the construction of important roads; …

…Tsierna (Orsova) is established as a colony.

Trajan begins a second campaign: invading Dacia in 106, his legions successfully besiege the capital.

Following the conclusion of the siege, Bicilis, a confidant of Decebalus, betrays his king, and leads the Romans to the Dacian treasure which, according to Jerome Carcopino, consists of one hundred and sixty-five thousand kilograms of pure gold and three hundred and thirty-one thousand kilograms of silver in the bed of the Sergetia River.

Decebalus had managed to flee with his family and many of his followers.

Trajan’s forces hunt down all Dacians who have fled or refused to immediately surrender.

Decebelus and his officers, apprehended by Roman cavalry, commit suicide by drinking hemlock.

The Romans under Trajan add parts of present Romania to Moesia Inferior.

Because Moesia is a frontier region, the area must be garrisoned by Roman troops, whose legionary camps are built along the Danube River.

Several Greek cities spring up near the mouth of the Danube, and the other principal cities of Moesia grow out of the legionary camps along the Danube; these, too, have sizable Greek elements in their population, given the predominantly Greek composition of the legions here.