The Byzantine Empire was ruled by emperors of the dynasty of Heraclius between 610 and 711. The Heraclians presided over a period of cataclysmic events that were a watershed in the history of the Empire and the world. Heraclius, the founder of his dynasty, was of Armenian and Cappadocian (Greek) origin. At the beginning of the dynasty, the Empire's culture was still essentially Ancient Roman, dominating the Mediterranean and harbouring a prosperous Late Antique urban civilization. This world was shattered by successive invasions, which resulted in extensive territorial losses, financial collapse and plagues that depopulated the cities, while religious controversies and rebellions further weakened the Empire.

Late antiquity is sometimes defined as spanning from the end of classical antiquity to the local start of the Middle Ages, from around the late 3rd century up to the 7th or 8th century in Europe and adjacent areas bordering the Mediterranean Basin depending on location. The popularisation of this periodization in English has generally been credited to historian Peter Brown, who proposed a period between 150–750 AD. The Oxford Centre for Late Antiquity defines it as "the period between approximately 250 and 750 AD". Precise boundaries for the period are a continuing matter of debate. In the West, its end was earlier, with the start of the Early Middle Ages typically placed in the 6th century, or even earlier on the edges of the Western Roman Empire.