In 602 Maurice, with the lack of money as always dictating policy, decreed that the army should stay for winter beyond the Danube. The exhausted troops mutinied against the Emperor. Probably misjudging the situation, Maurice repeatedly ordered his troops to start a new offensive rather than return to winter quarters. His troops gained the impression that Maurice no longer understood the military situation and proclaimed Phocas their leader. They demanded that Maurice abdicate and proclaim as successor either his son Theodosius or General Germanus. Both men were accused of treason.

As riots broke out in Constantinople, the Emperor, taking his family with him, left the city on a warship heading to Nicomedia, while Theodosius headed east to Persia (historians are not sure whether he had been sent there by his father or if he fled there). Phocas entered Constantinople in November and was crowned emperor. His troops captured Maurice and his family and brought them to the harbor of Eutropius at Chalcedon. Maurice was murdered at the harbor of Eutropius on 27 November 602. The deposed emperor was forced to watch his five younger sons executed before he was beheaded himself.