Justinian II, nicknamed "the Slit-Nosed", was the last Byzantine emperor of the Heraclian dynasty, reigning from 685 to 695 and again from 705 to 711. Like his namesake, Justinian I, Justinian II was an ambitious and passionate ruler who was keen to restore the Roman Empire to its former glories. However, he responded brutally to any opposition to his will and lacked the finesse of his father, Constantine IV. Consequently, he generated enormous opposition to his reign, resulting in his deposition in 695 in a popular uprising. He only returned to the throne in 705 with the help of a Bulgar and Slav army. His second reign was even more despotic than the first, and in 711 he was killed by mutinous soldiers.

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.