A few weeks later the battle was renewed on the plain of Mardia in Thrace. Licinius had evidently been strongly reinforced from Asia, for, though he was again defeated after a hotly contested battle, he was able to effect an orderly retreat and draw off his beaten troops without disorder—a rare thing in the annals of Roman warfare, where defeat usually involved destruction. Constantine is said to have owed his victory to his superior generalship and to the skill with which he timed a surprise attack of five thousand of his men upon the rear of the enemy. Yet we may be certain that he would not have consented to treat with Licinius for peace had he not had considerable cause for anxiety about the final issue of the campaign. However, his two victories, while not sufficiently decisive to enable him to dictate any terms he chose, at least gave him the authoritative word in the negotiations which ensued, and sealed the doom of the unfortunate Valens, whom Licinius had just appointed Cæsar. When Licinius’s envoy spoke of his two imperial masters, Licinius and Valens, Constantine retorted that he recognised but one, and bluntly stated that he had not endured tedious marches and won a succession of victories, only to share the prize with a contemptible slave. Licinius sacrificed his lieutenant without compunction and consented to hand over to Constantine Illyria and its legions, with the important provinces of Pannonia, Dalmatia, Moesia, and Dacia. The only foothold left him on the Continent of Europe, out of all that had previously been included in the eastern half of the Empire, was the province of Thrace.