He accordingly concentrated his forces more and more, strengthened himself by every means in his power, and advanced further and further into the interior of the country. Antigonus began to retire, desirous, perhaps, of reaching some ground where he could post himself advantageously. Pyrrhus, acting with his customary energy, soon overtook the enemy. He came up with the rear of Antigonus's army in a narrow defile among the mountains; at least, the place is designated as a narrow defile by the ancient historian who narrates these events, though, from the number of men that were engaged in the action which ensued, as well as from the nature of the action itself, as a historian describes it, it would seem that there must have been a considerable breadth of level ground in the bottom of the gorge.
The main body of Antigonus's troops was the phalanx. The Macedonian phalanx is considered one of the most extraordinary military contrivances of ancient times. The invention of it was ascribed to Philip, the father of Alexander the Great, though it is probable that it was only improved and perfected, and brought into general use, but not really originated by him. The single phalanx was formed of a body of about four thousand men. These men were arranged in a compact form, the whole body consisting of sixteen ranks, and each rank of two hundred and fifty-six men. These men wore each a short sword, to be used in cases of emergency, and were defended by large shields. The main peculiarity, however, of their armor, and the one on which the principal power of the phalanx depended as a military body, was in the immensely long spears which they carried. These spears were generally twenty-one, and sometimes twenty-four feet long. The handles were slender, though strong, and the points were tipped with steel. The spears were not intended to be thrown, but to be held firmly in the hands, and pointed toward the enemy; and they were so long, and the ranks of the men were so close together, that the spears of the fifth rank projected several feet before the men who stood in the front rank. Thus each man in the front rank had five steel-pointed spears projecting to different distances before him, while the men who stood in ranks further behind rested their spears upon the shoulders of those who were before them, so as to elevate the points into the air.
The men were protected by large shields, which, when the phalanx was formed in close array, just touched each other, and formed an impregnable defense. In a word, the phalanx, as it moved slowly over the plain, presented the appearance of a vast monster, covered with scales, and bristling with points of steel-a sort of military porcupine, which nothing could approach or in any way injure. Missiles thrown toward it were intercepted by the shields, and fell harmless to the ground. Darts, arrows, javelins, and every other weapon which could be projected from a distance, were equally ineffectual, and no one could come near enough to men thus protected to strike at them with the sword. Even cavalry were utterly powerless in attacking such chevaux de frise as the phalanx presented. No charge, however furious, could break its serrated ranks; an onset upon it could only end in impaling the men and the horses that made it together on the points of the innumerable spears.
To form a phalanx, and to maneuver it successfully, required a special training, both on the part of the officers and men, and in the Macedonian armies the system was carried to very high perfection. When foreign auxiliaries, however, served under Macedonian generals, they were not generally formed in this way, but were allowed to fight under their own leaders, and in the accustomed manner of their respective nations. The army of Antigonus, accordingly, as he was retiring before Pyrrhus, consisted of two portions. The phalanx was in advance, and large bodies of Gauls, armed and arrayed in their usual manner, were in the rear. Of course, Pyrrhus, as he came up with this force in the ravine or valley, encountered the Gauls first. Their lines, it would seem, filled up the whole valley at the place where Pyrrhus overtook them, so that, at the outset of the contest, Pyrrhus had them only to engage. There was not space sufficient for the phalanx to come to their aid.
Besides the phalanx and the bodies of Gauls, there was a troop of elephants in Antigonus's army. Their position, as it would seem, was between the phalanx and the Gauls. This being the state of things, and Pyrrhus coming up to the attack in the rear, would, of course, encounter first the Gauls, then the elephants, and, lastly, the most formidable of all, the phalanx itself.
Pyrrhus advanced to the attack of the Gauls with the utmost fury, and, though they made a very determined resistance, they were soon overpowered and almost all cut to pieces. The troop of elephants came next. The army of Pyrrhus, flushed with their victory over the Gauls, pressed eagerly on, and soon so surrounded the elephants and hemmed them in, that the keepers of them perceived that all hope of resistance was vain. They surrendered without an effort to defend themselves. The phalanx now remained. It had hastily changed its front, and it stood on the defensive. Pyrrhus advanced toward it with his forces, bringing his men up in array in front of the long lines of spears, and paused. The bristling monster remained immovable, evincing no disposition to advance against its enemy, but awaiting, apparently, an attack. Pyrrhus rode out in front of his lines and surveyed the body of Macedonians before him. He found that he knew the officers personally, having served with them before in the wars in which he had been engaged in Macedon in former years. He saluted them, calling them by name. They were pleased with being thus remembered and recognized by a personage so renowned. Pyrrhus urged them to abandon Antigonus, who had, as he maintained, no just title to the crown, and whose usurped power he was about to overthrow, and invited them to enter into his service, as the ancient and rightful sovereign of their country. The officers seemed much disposed to listen to these overtures; in fine, they soon decided to accede to them. The phalanx went over to Pyrrhus's side in a body, and Antigonus, being thus deprived of his last remaining support, left the field in company with a few personal followers, and fled for his life.
Of course, Pyrrhus found himself at once in complete possession of the Macedonian kingdom. Antigonus did not, indeed, entirely give up the contest. He retreated toward the coast, where he contrived to hold possession, for a time, of a few maritime towns; but his power as King of Macedon was gone. Some few of the interior cities attempted, for a time, to resist Pyrrhus's rule, but he soon overpowered them. Some of the cities that he thus conquered he garrisoned with Gauls.
Of course, after such a revolution as this, a great deal was required to be done to settle the affairs of the government on their new footing, and to make the kingdom secure in the hands of the conqueror; but no one in the least degree acquainted with the character and tendencies of Pyrrhus's mind could expect that he would be at all disposed to attend to these duties. He had neither the sagacity to plan nor the steadiness of purpose to execute such measures. He could conquer, but that was all. To secure the results of his conquests was utterly beyond his power.