While Constantius was thus engaged struggling against the barbarians on the plains of Asia, Constantine was plotting an expedition against his brother Constans, who was a mere boy, proud, conceited, and incompetent. But the race is not always to the swift. Constantine, with a large army, crossed the Julian Alps, and invaded Italy to wrest that kingdom from his brother. But Constans, whom Constantine had despised, had able generals. They lured Constantine into an ambush, routed his army, killed him, and annexed all his realms to the Western empire. Soon after this, a sturdy general, Magnentius, formed a conspiracy in the army, killed young Constans, and was proclaimed emperor by the soldiers. All the Western and Central realms acknowledged him. Constantius, from the East, put his veteran army in motion, and advanced from the plains of Mesopotamia to make war upon Magnentius and to avenge his brother’s death. The whole then known world was thrown into commotion by this strife, which was to decide who should be master of this world. War and woe held high carnival. There were famine, pestilence, and death, smouldering towns, blood-stained fields covered with the slain, and despairing shrieks of widows and orphans. The hostile armies met in vast numbers on the River Drave, not far from its entrance into the Danube. It was one of those battles which was to decide the fate of the world. Constantius, aware of the military ability of his antagonist, wisely, but not heroically, retired to the tower of a church where he could overlook the field. He left the conduct of the day to one of his veteran generals. A fiercer battle than that which ensued was perhaps never fought. Roman and barbarian legions were intermingled, blending in the fight. The air was darkened with stones, arrows, and javelins. Clouds of horsemen, glittering in their polished armor, swept the field like moving statues of steel, trampling the dead and wounded beneath iron hoofs. Night terminated the conflict. The army of Magnentius, overpowered by numbers, was almost annihilated. Fifty-four thousand were left dead upon the field. They sold their lives dearly. A still greater number of the troops of Constantius lay drenched in blood by their side. Over a hundred and twenty thousand perished in this one battle. Thus did Rome, in civil strife, devour her own children. Thus was the way opened for the irruption and triumph of the barbarians. In the darkness of night, Magnentius, throwing aside his imperial mantle, mounted a fleet horse, and, accompanied by a few friends, attempted to escape through the Julian Alps. He reached the city of Aquileia, at the head of the Adriatic Sea, not far from the present city of Trieste. Here, amidst the pathless defiles of the mountains, he rallied his surviving troops around him, and made another stand.