The Muslim conquest of Egypt, led by the army of 'Amr ibn al-'As, took place between 639 and 646 AD and was overseen by the Rashidun Caliphate. It ended the seven-century-long period of Roman reign over Egypt that began in 30 BC. Byzantine rule in the country had been shaken, as Egypt had been conquered and occupied for a decade by the Sassanid Iran in 618–629, before being recovered by the Byzantine emperor Heraclius. The caliphate took advantage of Byzantines' exhaustion and captured Egypt ten years after its reconquest by Heraclius.