Rome finally subjugates recalcitrant Illyrian tribes in the western Balkans in CE 9, during the reign of Emperor Tiberius.

The Romans divide the lands that make up present-day Albania among the provinces of Macedonia, Dalmatia, and Epirus.

For about four centuries, Roman rule will bring the Illyrian-populated lands economic and cultural advancement and end most of the clashes among local tribes.

The Illyrian mountain clansmen retain local authority but pledge allegiance to the emperor and acknowledge the authority of his envoys.

During a yearly holiday honoring the Caesars, the Illyrian mountaineers swear loyalty to the emperor and reaffirm  their political rights.

A form of this tradition, known as the kuvend, has survived to the present day in northern Albania.

 

The Romans establish numerous military camps and colonies in Illyria and completely latinize the coastal cities.

They also oversee the construction of aqueducts and roads, including the Via Egnatia, a famous military highway and trade route that leads from Durres through the Shkumbin River valley to Macedonia and Byzantium (later Constantinople).

Copper, asphalt, and silver are extracted from the mountains.

The main exports are wine, cheese, and oil, as well as fish from Lake Scutari and Lake Ohrid.

Imports include tools, metalware, luxury goods, and other manufactured articles.

Apollonia becomes a cultural center; Julius Caesar himself sends his nephew, later the Emperor Augustus, to study there.

The region known as Dalmatia, a narrow coastal strip on the eastern side of the Adriatic Sea lying west of the Dinaric Alps and bordered by Istria in the north and by Kotor Bay in the south, had been the northern part of the Illyrian kingdom between the fourth century BCE until the Illyrian Wars in the 220s BCE and 168 BCE when the Roman Republic established its protectorate south of the river Neretva.

The area north of the Neretva had been slowly incorporated into Roman possessions until the province of Illyricum was formally established around 32-27 BCE.

The region had then become part of Illyricum.

The Dalmatians between 6 and 9 CE, had raised the last in a series of revolts together with the Pannonians, but the Romans have finally crushed the revolt in CE 10 and split llyricum into two provinces, Pannonia and Dalmatia.

Christianity apparently comes in the late first century CE to the Illyrian-populated lands.

Writings attributed to Paul of Tarsus, the religion's founder, state that he preaches in the Roman province of Illyricum (and legend holds that he visited Durrës. Paul is said to have been born in Tarsus, perhaps around CE 10, and to have died at Rome in about 67, but there are no reliable sources for Paul's life outside the New Testament, in which the primary source is his own letters.)

Latin culture permeates southeastern Europe over the next five hundred years.

The Romans divide their western Balkan territories into separate provinces.

New roads link fortresses, mines, and trading towns.

The Romans introduce viticulture in Dalmatia, institute slavery, and dig new mines.

Agriculture thrives in the Danube Basin, and towns throughout the country blossom into urban areas with forums, temples, water systems, coliseums, and public baths.

In addition to gods of the Greco-Roman pantheon, Roman legionnaires bring the mystic cult of Mithras from Persia.

The Roman army also recruits natives of the conquered regions, and five sons of Illyrian peasants will rise through the ranks to become emperor.

The Illyrian, Celtic, and Thracian languages will all eventually die out, but the centuries of Roman domination will fail to create cultural uniformity.

Severus again attacks Clodius Albinus to the northwest of the city, defeating the latter’s army on the nineteenth of February 197 in the bloody and decisive Battle of Lugdunum.

Dio Cassius describes three hundred thousand men involved in the battle: although this is one of the largest battles involving Roman armies known, this number is assumed to be an exaggeration.

The actual size of Severus’s army may be closer to seventy-five thousand men, mostly composed of Illyrian, Moesian and Dacian legions.

Albinus commits suicide in a house near the Rhône; his head is sent to Rome as a warning to his supporters.

His defeated cohorts are dissolved and the victorious legions punish those in Lugdunum who had supported Albinus, by confiscation, banishment, or execution.

The city is plundered or at least severely damaged by the battle.

Legio I Minervia will remain camped in Lugdunum from 198 to 211.

Historical and archaeological evidence indicates that Lugdunum never fully recovers from the devastation of this battle.

Severus departs for Italy and the East to resume the war against Parthia.

Julia has also alienated the army by her extreme parsimony, and neither she nor her son are strong enough to impose military discipline.

Mutinies become frequent in all parts of the Empire; in Rome, the Praetorian Guard becomes infuriated by the actions of the praetorian praefect Ulpian, whose curtailment of the privileges granted to the Praetorian Guard by Elagabalus has provoked their enmity, and he has narrowly escaped their vengeance; ultimately he is murdered in the palace at the feet of the Emperor, in the course of a three-day riot between the soldiers and the mob.

Another mutiny forces the retirement of Cassius Dio from his command.

Fresh mutinies perpetually break out in the provinces of the Empire—in Illyricum, in Mauretania, in Armenia, in Mesopotamia and in Germania—as his officers are murdered and the emperor’s authority is disregarded.

The Roman Empire is plagued by internal strife and economic crisis  in the third century CE. Two ethnic Illyrian emperors, both born in Southeastern Europe, take decisive steps to prolong the empire’s survival.

• Emperor Diocletian, born in Dalmatia, implements strong central control, establishes a bureaucratic system, and abolishes the last remnants of Roman republican institutions. In an effort to strengthen loyalty to the state, he launches a persecution of Christians, seeking to reduce their allegiance to the church.
• Emperor Constantine, born near Naissus (modern Niš, Serbia), reunites the empire after years of turmoil, introduces dynastic succession, and in 330 CE, founds a new capital at Byzantium, later named Constantinople. He also legalizes Christianity, marking a pivotal shift in Roman religious policy.

The Holy See had been vacant for nearly a year following the martyrdom of Sixtus II, due yo difficulty in electing a new Pope during the violent persecution which Christians faced.

When the persecution had begun to subside, Dionysius was raised to the office of Bishop of Rome.

Upon his father's capture, Gallienus had put an end to the persecution of the Christians and given the Church legal status, preferring to fight the new religion through intellectual means; to that end, he favors the ancient Greek cults (Demeter of Eleusis) and protects the Neoplatonist philosopher Plotinus.

These initiatives increase the number of his enemies, particularly among the patriotic senators and the Pannonian generals.

Gallienus himself is left in control only of Italy and the Balkans.

Mediolanum (Milan), having acquired increasing prestige and economic power over the past few centuries, has become the second city of the Empire behind Rome itself.

Manius Acilius Aureolus, commander of the field army in Mediolanum, has succeeded to recover Raetia to the central empire by 268.

In this same year, he is in Mediolanum, where he rebels against Gallienus, supporting Postumus, who has carved the Gallic Empire for himself out of the northern Roman provinces, and minting coins in his name.

Aureolus sends letters to Postumus, asking him to come and invade Italy, but Postumus refuses, and leaves Aureolus to his fate.

Gallienus, having left his “Scythian war,” returns to Italy to besiege Aureolus in Mediolanum, but is soon afterwards assassinated in a plot hatched, apparently, by his own staff officers.

After the death of the emperor, Aureolus claims the purple with the support of his army, but a large contribution to the troops secures the election of Gallienus' cavalry commander, who, as Marcus Aurelius Valerius Claudius, or Claudius II, is the first Illyrian to occupy the imperial throne.

Claudius continues the siege, rejecting Aureolus' attempts to sue for peace.

Soon after Aureolus surrenders, hoping for mercy, he is instead put to death by the Praetorian Guard, which has not forgiven his treachery.