What place did the Byzantine empire occupy in the world of the early Middle Ages?

In the early Middle Ages, Byzantium (the former Eastern Roman Empire) was one of the most developed states of its time and stood out sharply against the background of the barbarian kingdoms of the Ostrogoths, Visigoths, Lombards, Burgundians and Franks, as well as against the background of neighboring peoples – Slavs, Avars, Huns, who are not unsuccessfully plundered its territory.

During its heyday under Emperor Justinian I in the middle of the 6th century, Byzantium controlled the eastern Mediterranean, the peninsula of Asia Minor, Crimea, part of Georgia, the Middle East, Egypt, the coast of Libya, Tunisia and Algeria, southern Spain, Sardinia, Corsica, the entire territory of modern Italy and the whole Balkan Peninsula (lands south of the Danube).