THE EMPIRE SHRINKS

The reign of Heraclius (r.610-641) sees the Byzantine Empire shrink. Although eventually successful against the Sassanians, a new threat in the south – the Rashidun Caliphate – captures Egypt, Syria, Mesopotamia and Armenia. Attempts to shore up the empire in the west and forge alliances with western allies have varied results.

The Sassanians fought against Heraclius even reaching Constantinople, but the city’s walls saved it