The Historians' History of the World 06 [The Early Roman Empire]

Arch of Constantine, Rome

The first battle was fought near Cibalis, a city of Pannonia, situated on the river Savus, about fifty miles from Sirmium. From the inconsiderable forces which in this important contest two such powerful monarchs brought into the field, it may be inferred that the one was suddenly provoked, and that the other was unexpectedly surprised. The emperor of the West had only twenty thousand, and the sovereign of the East no more than five-and-thirty thousand men. The inferiority of number was, however, compensated by the advantage of the ground. Constantine had taken post in a defile about half a mile in breadth, between a steep hill and a deep morass, and in that situation he steadily expected and repulsed the first attack of the enemy. He pursued his success, and advanced into the plain. But the veteran legions of Illyricum rallied under the standard of a leader who had been trained to arms in the school of Probus and Diocletian. The missile weapons on both sides were soon exhausted; the two armies, with equal valour, rushed to a closer engagement of swords and spears, and the doubtful contest had already lasted from the dawn of the day to a late hour of the evening, when the right wing, which Constantine led in person, made a vigorous and decisive charge. The judicious retreat of Licinius saved the remainder of his troops from a total defeat; but when he computed his loss, which amounted to more than twenty thousand men, he thought it unsafe to pass the night in the presence of an active and victorious enemy. Abandoning his camp and magazines, he marched away with secrecy and diligence at the head of the greatest part of his cavalry, and was soon removed beyond the danger of a pursuit. His diligence preserved his wife, his son, and his treasures, which he had deposited at Sirmium.[56] Licinius passed through that city, and breaking down the bridge on the Savus, hastened to collect a new army in Dacia and Thrace. In his flight he bestowed the precarious title of Cæsar on Valens, his general of the Illyrian frontier.[57]

The plain of Mardia in Thrace was the theatre of a second battle, no less obstinate and bloody than the former. The troops on both sides displayed the same valour and discipline; and the victory was once more decided by the superior abilities of Constantine.c Licinius drew up his army [says Zosimus] in order of battle, extending from a mountain which is above the town two hundred stadia, as far as the junction of another river with the Hebrus; thus the armies continued opposite to each other for several days. Constantine, observing where the river was least broad, concerted this plan. He ordered his men to bring trees from the mountain, and to tie ropes around them, as if he intended to throw a bridge over the river for the passage of his army. By this stratagem he deluded the enemy, and, ascending a hill on which were thick woods sufficient to conceal any that were in them, he planted there five thousand archers and eight hundred horse. Having done this, he crossed the Hebrus at the narrowest place, and so surprised the enemy that many fled with all their speed, while others, who were amazed at his unexpected approach, were struck with wonder at his coming over so suddenly. In the meantime, the rest of his army crossed the river in security, and a great slaughter commenced. Nearly thirty thousand fell; and about sunset Constantine took their camp, while Licinius, with all the forces he could muster, hastened through Thrace to his ships.d

The loss of two battles reduced the fierce spirit of Licinius to sue for peace. His ambassador Mistrianus was admitted to the audience of Constantine; he expatiated on the common topics of moderation and humanity, which are so familiar to the eloquence of the vanquished; represented, in the most insinuating language, that the event of the war was still doubtful, whilst its inevitable calamities were alike pernicious to both the contending parties; and declared, that he was authorised to propose a lasting and honourable peace in the name of the two emperors, his masters. Constantine received the mention of Valens with indignation and contempt.

“It was not for such a purpose,” he sternly replied, “that we have advanced from the shores of the western ocean in an uninterrupted course of combats and victories, that, after rejecting an ungrateful kinsman, we should accept for our colleague a contemptible slave. The abdication of Valens is the first article of the treaty.” It was necessary to accept this humiliating condition; the unhappy Valens, after a few days’ reign, was deprived of the purple and of his life. As soon as this obstacle was removed, the tranquillity of the Roman world was easily restored. The successive defeats of Licinius had ruined his forces, but they had displayed his courage and abilities. His situation was almost desperate, but the efforts of despair are sometimes formidable; and the good sense of Constantine preferred a great and certain advantage to a third trial of the chance of arms. He consented to leave his rival, or, as he again styled Licinius, his friend and brother, in the possession of Thrace, Asia Minor, Syria, and Egypt; but the provinces of Pannonia, Dalmatia, Dacia, Macedonia, and Greece were yielded to the Western Empire; and the dominions of Constantine now extended from the confines of Caledonia to the extremity of Peloponnesus. It was stipulated by the same treaty that three royal youths, the sons of the emperors, should be called to the hopes of the succession. Crispus and the young Constantine were soon afterwards declared cæsars in the West, while the younger Licinius was invested with the same dignity in the East. In this double proportion of honours, the conqueror asserted the superiority of his arms and power.

THE LONG TRUCE BETWEEN THE EMPERORS; REFORMS OF CONSTANTINE