The rise of Phocas was marked by brutality and blood.

Despite the fact that Emperor Maurice was in many respects a capable ruler and general, by the end of his reign he had made himself deeply unpopular with the army through a series of cost-cutting measures. Most inflammatory was his decision to order troops to winter north of the Danube rather than returning to Byzantine territory, which was seen as both dangerous and insulting. To cap it all off, he also reduced military pay. Subsequently, the Danubian army mutinied in 602. Phocas quickly emerged as their leader despite being a junior officer, a centurion by some accounts. He was chosen partly perhaps because more senior officers were unwilling to take the risk of open revolt.

Additionally, Maurice failed to secure the loyalty of the capital. The circus factions, the Blues and Greens, turned against him and there was popular unrest in the city.  Maurice quickly fled with his family, was captured, and was executed along with his sons in November 602. The killing of his sons before his eyes before his own execution was recorded by contemporaries as particularly brutal.