Phocas' brutal repression sparked a succession crisis that ensued as the general Heraclius sent his nephew Nicetas to attack Egypt, enabling his son Heraclius the younger to claim the throne in 610. Phocas, an unpopular ruler who is invariably described in Byzantine sources as a "tyrant", was eventually deposed by Heraclius, having sailed from Carthage. Around the same time, the Persians completed their conquest of Mesopotamia and the Caucasus, and in 611 they overran Syria and entered Anatolia, occupying Caesarea. Having expelled the Persians from Anatolia in 612, Heraclius launched a major counter-offensive in Syria in 613. He was decisively defeated outside Antioch by Shahrbaraz and Shahin, and the Roman position collapsed.