Theodosius

During his Balkan Campaigns, Emperor Maurice and his family were murdered by Phocas in November 602 after a mutiny.[12] Khosrau II (Chosroes) of the Sassanid Empire had been restored to his throne by Maurice, and they had remained allies.

Thus, the Persian King Khosrau II seized the pretext to attack the Byzantine Empire and reconquer the Byzantine province of Mesopotamia.

Khosrau had at his court a man who claimed to be Maurice's son Theodosius, and Khosrau demanded that the Byzantines accept this Theodosius as Emperor.