Bulgars and Slavs

In 479, Emperor Zeno first allied himself with the 'so-called Bulgarians', who lived between Constantinople and the Adriatic coast. John of Antioch records this event. In subsequent years, Bulgars living in Illyria and Thrace raided and plundered those territories. In 494, they attacked and withdrew before the Byzantines noticed them.

In 501, Bulgars invaded Illyricum and Thrace. These are among the earliest accounts of their presence in the regions, provided by John Zonaras and Theophanes the Confessor.

After the Hunnic state broke up in 453, Slavs crossed the Carpathians and settled in Transylvania in the second half of the fifth century. In 519, during Emperor Justinian I's reign, the first Slavic raid across the Danube, by the Antes, was recorded.

In the sixth century, Slavs settled along the lower Danube. In the following centuries, they predominated across the Balkan Peninsula, occupying Moesia, Thrace, Macedonia, the Rhodopes, the Aegean region, Albania, Greece, the Adriatic coast and the central Peloponnese. They also settled in western Asia Minor. This period was characterised by changes in populations and territorial boundaries, including Slavic settlement and influence in the Balkans.