A revolt within the city soon afterwards resulted in the abdication of the reigning emperor Maurice, and in the elevation of Phocas to the throne, which seems to have been accomplished by one of the circus factions against the wish of the troops.
Phocas proved entirely incapable of governing the empire.
As early as 970 the recovery of the territories lost to Mahommedanism in the East had been begun by emperors like Nicephoras Phocas and John Zimisces: they had pushed their conquests, if only for a time, as far as Antioch and Edessa, and the temporary occupation of Jerusalem is attributed to the East Roman arms. At the opposite end of the Mediterranean, in Spain, the Omayyad caliphate was verging to its fall: the long Spanish crusade against the Moor had begun; and in 1018 Roger de Toeni was already leading Normans into Catalonia to the aid of the native Spaniard.
At the beginning of his reign he favoured the Christians; but when in 602 Maurice had been murdered by Phocas, he began war with Rome to avenge his death.
At last, in 622, the emperor Heraclius (who had succeeded Phocas in 610) was able to take the field.