Octavian has fought three campaigns in Illyria and Dalmatia from 35 BCE to 33 BCE.

The first mention of the province of Illyricum occurs in the context of Augustan settlement of 27 BCE, when it is assigned as a propraetorial province to imperial control.

The Romans divide the lands that make up present-day Albania among the provinces of Macedonia, …

The Thervings under Fritigern move south and east to Macedonia, where they take "protection money" from towns and cities rather than sacking them outright.

The Avars besiege Thessalonica, the second city of the Empire, in 586.

…Thessalonica are safe behind defensible walls.

Under these conditions, urban centers no longer are the basis of Roman society in the Balkans, however, as much of the indigenous population of the Balkans, Greeks included, …

Justinian II defeats the Bulgars of Macedonia with a great military campaign in 688–689, and is finally able to enter Thessalonica, the second most important imperial city in Europe.

The Empire's military position in the Balkans had collapsed in the early seventh century as a result of disastrous military ventures against the Persians and then the Arabs in the East, which had forced the effective abandonment of the Danube limes and opened the way for large-scale penetration of the Balkan hinterland by various Slavic tribes.

The Slavs had raided as far as southern Greece and the coasts of Asia Minor, and settled across the Balkan peninsula.

Most of the region's cities had been sacked or abandoned and only a few, including Thessalonica, remained occupied and in imperial hands.

The eastern coasts of the Peloponnese and Central Greece had remained in imperial hands as the theme of Hellas, while in the interior, various Slavic groups had established themselves.

A large native Greek population probably also had remained in the land, either mixed with the Slavs or in its own autonomous communities.

As elsewhere in Greece, a mostly peaceful modus vivendi had soon emerged between the Slavs and the remaining imperial strongholds, with the mainly agricultural Slavs trading with the imperial coastal towns.

Further north n the Greek mainland, smaller Slavic districts or sclaviniae by the turn of the eighth century had emerged around the fringes of imperial territory, ruled by their own archons, who receive imperial titles and recognize some form of imperial suzerainty.

Imperial authority across Greece had been greatly strengthened by the 783 campaign of the logothete Staurakios, who had ventured from Constantinople overland to Thessalonica and from there south to the Peloponnese, subduing the Slavs of those regions.

One Constantine (later called Cyril), a member of a noble family of Thessaloniki and the librarian of Constantinople's church of Hagia Sophia, resigns in 860 to join his brother Methodius, the abbot of a Greek monastery, in missionary journeys to the Khazars and Bulgarians.

Arab corsairs carry away some twenty thousand inhabitants of Thessalonica, the second city of the Empire, into slavery in North Africa and Crete.

Emperor Basil II launches his annual campaign against Bulgaria in the summer of 1014.

From Western Thrace via Serres, he reaches the valley of the Strumeshnitsa river where his troops are halted by a thick palisade guarded by an army under the personal command of the Bulgarian Emperor.

To divert the attention of the enemy, Samuel sends a large force under his general Nestoritsa to the south to attack the second largest city of the Empire, Thessaloniki.

Several days later, Nestoritsa reaches the fields to the west of the city or, according to other historians near the river of Galik, where the Bulgarians confronts a strong army led by the doux (governor) of Thessalonica, Theophylactus Botaniates and his son Michael.

The latter charges the Bulgarians but is surrounded.

In the fierce fighting, the Bulgarians suffer many casualties and pull back under the cover of archers.

A second attack of Michael and the Greek cavalry results in a complete defeat for Nestoritsa's troops and they flee.

The victorious Greeks capture many soldiers.

After securing Thessalonica, Botaniates joins Basil's army at Belasitsa.

Later in the summer, Botaniates and his army are defeated in the gorges to the south of Strumitsa and he perishes in the battle, killed by Samuel's son Gavril Radomir.

Nestoritsa, who survived the defeat, will surrender to Basil II four years later in 1018, after the Emperor enters the capital of Bulgaria, Ohrid.

…Petar II marches on Thessalonica, where the Emperor Michael IV is staying.

Defeated, he flees, leaving his treasury to a certain Michael Ivač.

The latter, who is probably a son of Ivač, a general under Samuel of Bulgaria, promptly turns over the bulk of the treasury to Petar outside the city.

Thessalonica remains in imperial hands, but …