During Shapur's invasion of Syria he captured important Roman cities like Antioch. The Emperor Valerian (253–260) marched against him and by 257 Valerian had recovered Antioch and returned the province of Syria to Roman control. The speedy retreat of Shapur's troops caused Valerian to pursue the Persians to Edessa. Valerian met the main Persian army, under the command of Shapur I, between Carrhae and Edessa, with units from almost every part of the Roman Empire, together with Germanic allies, and was thoroughly defeated and captured with his entire army.