While the exact size of his army remains unknown, Byzantine Emperor Heraclius feared a Persian advance before he could fully consolidate his troops.
Heraclius' route has been the subject of historical debate; some scholars suggest that he first reached an unidentified location near Caesarea in Cappadocia, though it is more widely believed that he marched directly east towards Pontus.
This tactical maneuver by Heraclius, described in poetic terms by the historian George of Pisidia, involved complex feints and reversals that caught the Persian forces off-guard.
Shahrbarāz attempted a counter-maneuver to outflank the Byzantines, culminating in a failed night assault, hindered by limited visibility due to a waning moon.
[4] Feigning a retreat with a small force, Heraclius prompted the Persians to break cover and pursue, at which point his elite unit, the Optimates, launched a decisive assault, inflicting significant losses.