§ 1. Almost all outstanding commanders, because they do not fight without a favorable opportunity, have discovered something new in forming a battle-line. Hence wedges, compact bodies, shears, towers, and saws. They call it a wedge when the battle-line is triangular. Vegetius, book 1, chapter 26. The Greeks call it ἔμβολον, “a ram”; in the time of Ammianus it was called the “boar’s head.” Suidas, drawing from Agathias, as translated by Lipsius, says:
“Their form of battle-line was like a beak. For it resembled the letter Δ. The front part, where it ended in a point, was covered and dense, because it was fortified on every side with shields. You might say that they had fashioned a boar’s head by this structure. But the legs on each side, arranged in depth according to ranks and cohorts and extended obliquely for the most part, gradually came together and separated until, having extended to the greatest breadth, they came to an end. Thus the middle space was left empty and the unprotected backs of the soldiers were visible rank by rank.”
The Franks and Romans employed it when they wished to break through a battle-line. But it must be used when a way must necessarily be made, for it is an altogether dangerous thing. Secondly, it must be used only when the enemy’s ranks are sparse; otherwise they will strike against a solid body. Thirdly, it must never be used when fighting against skilled men, for it is easy for them either to oppose a dense battle-line or to open their ranks so as to enclose the wedge in the middle. “Wedge” is sometimes said of the Macedonian phalanx and of another form of battle-line, as Lipsius teaches.
§ 2. The inverted wedge is the forceps, or shears; the wedge is received or worn away by this formation. The formation called a tower, and the one called a brick, do not differ from the preceding forms. In it men repeatedly advance and withdraw.
The Polybian legion had one hundred men in its front and thirty-four inward along its side; the triarii were half as numerous as the other divisions of the legion. In antiquity a soldier had three feet in every direction, so that he could handle his weapons conveniently, and this was the minimum. Polybius gives this account, but Vegetius speaks otherwise in book 3, chapter 14:
“Individual armed men have customarily occupied three feet each in a straight line. That is, within one thousand paces, one thousand six hundred and sixty-six infantrymen are arranged lengthwise, so that the battle-line does not show daylight through it and yet there is space for handling weapons. But they wished the distance in breadth between one rank and the rank behind it to be six feet, so that the combatants might have space to advance and withdraw; for missiles are cast more violently with a leap and a run.
“In these first two ranks men mature in age, confident from experience, and protected also by heavier arms are stationed. These, like a wall, must be compelled neither to give ground nor to follow another, lest they throw the ranks into disorder; instead they must receive the advancing adversaries and repel or rout them by standing and fighting. The third rank is formed of the swiftest light-armed troops, young archers, and good javelin throwers, whom they formerly called ferentarii. The fourth rank likewise is formed of the nimblest shield-bearers, younger archers, and those who fight vigorously with darts and martiobarbuli, which they call lead-weighted darts; these were called the light-armed troops.
“One must therefore know that, while the first two ranks remain standing, the third and fourth ranks always go forward first to provoke the enemy with missiles and arrows. If they have been able to turn the enemy to flight, they themselves pursue together with the cavalry. But if they have been repulsed by the enemy, they return to the first and second battle-lines and are received between them into their own places. The first and second battle-lines sustain the whole war when matters have come, as they say, to swords and javelins.
“In the fifth battle-line were sometimes placed wagon-mounted ballistae, hand-ballista men, staff-slingers, and slingers. Staff-slingers are those who cast stones with staff-slings. A staff-sling is a staff four feet long, to the middle of which a leather sling is fastened; propelled with both hands, it directs stones almost in the manner of an onager. Slingers are those who, with a sling made of flax or woven hair—for they say these are better—direct stones by whirling an arm around the head. Those who lacked them fought in this rank either with stones cast by hand or with missiles; they called them accensi, as being younger and added afterward.
“After all the others, the sixth rank was held by the strongest warriors, bearing shields and fortified with every kind of weapon; the ancients called them triarii. These men, so that, rested and fresh, they might attack the enemy more vigorously, customarily sat behind the last battle-lines. For if anything had befallen the first ranks, the entire hope of restoration depended upon their strength.”
And in chapter 15:
“Now that the manner in which battle-lines ought to be formed has been explained, I shall set forth the podismos, or measurement, of the formation itself. Within one thousand paces of ground, one battle-line receives one thousand six hundred and sixty-six infantrymen, because individual combatants occupy three feet each. But if you wish to arrange six battle-lines within one thousand paces of ground, nine thousand nine hundred and ninety-six infantrymen are necessary. If, however, you wish to extend this number in three ranks, you will encompass two thousand paces. But it is better to make more battle-lines than to spread out the soldiery.
“We have said, moreover, that six feet in breadth ought to intervene in the rear between the individual battle-lines, and the combatants themselves, standing, occupy one foot each. Accordingly, if you arrange six battle-lines, an army of ten thousand men will occupy forty-two feet in breadth and one thousand paces in length. But if you wish to arrange them in three, an army of ten thousand will occupy twenty-one feet in breadth and two thousand paces in length. According to this calculation, whether there are twenty thousand or thirty thousand infantrymen, they will without any uncertainty or difficulty be able to be arranged according to the measure of the podismos. Nor is the commander deceived when he knows how many armed men a place can contain.
“Finally, if the place is narrower, or if the multitude is sufficient, it is fitting for even nine or more battle-lines to be formed from them. For it is more expedient that they fight close together than separated too widely. For if the battle-line has been made too thin, it is swiftly broken through by an assault of the adversaries, and afterward no remedy can exist. Which numbers ought to be arranged on the right wing, which on the left, and which in the middle is either observed by custom according to their ranks, or certainly changed according to the character of the enemy.”
§ 3. The form of the battle-line is now determined according to the advantage of the places and according as the enemy establishes his own. Account is also taken of nations, some of which are more disposed toward certain forms; and therefore, if that form is adopted, they fight more skillfully and confidently. When the front is broad, they wish it to exceed the depth by one third; when the battle-line is deeper than it is broad, they require the same proportion. Nevertheless, I understand that this must be varied if the enemy’s battle-line or the situation of the places requires it.
The wings of firearm-bearing cavalry surround the flanks. Light-armed cavalry fights by troops; cuirassiers preserve their ranks more closely. Mendoza compares the battle-line to a human body. He says that firearm-bearers are like the hands and feet; light cavalry, the lower legs and arms; cuirassiers, the hips; legions of infantry, the breast; the commander, the head; and the baggage, the belly. The man who attacks the enemy puts forward his right hand; if he must wrestle, he exerts himself with all his strength at once.
When there are lancers and firearm-bearing cavalrymen, the latter occupy the battle-lines and begin the engagement a little sooner than the lancers; the lancers cast down those whose order has been disturbed. They employ these methods even in conflicts between few men. Some think that lancers are joined to others disadvantageously because they can effect nothing at a distance. But when joined to cavalrymen carrying long firearms and to infantrymen whom they call musketeers, they are useful. Therefore they must by no means be neglected.