The light infantry were variously armed with slings and darts as well as swords, and commonly wore a shaggy cap, in imitation of the head of some wild beast, of which the skirt hung over their shoulders. The troops of the line wore greaves on the legs and heavy iron-bound sandals on the feet. These last were called caligæ, from which the emperor Caius Cæsar obtained the name of Caligula, in consequence of having worn them in his youth among the soldiery.
The cavalry were armed with spears and wore a coat of mail of chain work, or scales of brass or steel, often plated with gold, under which was a close garment that reached to their buskins. The helmet was surmounted with a plume, and with an ornament distinctive of each rank, or with some device according to the fancy of the wearers, and which was then, as now in heraldry, denominated the crest. This term was crista, derived from the resemblance of the ornament to the comb of a cock.
The Romans made no use of saddles or stirrups, but merely cloths folded according to the convenience of the rider.
Among the instruments used in war were towers consisting of different stories, from which showers of darts were discharged on the townsmen by means of engines called catapultæ, balistæ, and scorpiones.
But the most dreadful machine of all was the battering ram: this was a long beam like the mast of a ship, and armed at one end with iron, in the form of a ram's head, whence it had its name. It was suspended by the middle, with ropes or chains fastened to a beam which lay across two posts, and hanging thus equally balanced, it was violently thrust forward, drawn back, and again pushed forward, until by repeated strokes it had broken down the wall.
The discipline of the army was maintained with great severity; officers were exposed to degradation for misconduct, and the private soldier to corporal punishment. Whole legions who had transgressed their military duty were exposed to decimation, which consisted in drawing their names by lot, and putting every tenth man to the sword.
The most common rewards were crowns of different forms; the mural crown was presented to him who in the assault first scaled the rampart of a town; the castral, to those who were foremost in storming the enemy's entrenchments; the civic chaplet of oak leaves, to the soldier who saved his comrade's life in battle, and the triumphal laurel wreath to the general who commanded in a successful engagement. The radial crown was that worn by the emperors.
When an army was freed from a blockade, the soldiers gave their deliverer a crown called obsidionalis, made of the grass which grew in the besieged place; and to him who first boarded the ship of an enemy, a naval crown.
But the greatest distinction that could be conferred on a commander, was a triumph; this was granted only by the senate, on the occasion of a great victory. When decreed, the general returned to Rome, and was appointed by a special edict to the supreme command in the city; on the day of his entry, a triumphal arch was erected of sculptured masonry, under which the procession passed.
First came a detachment of cavalry, with a band of military music preceding a train of priests in their robes, who were followed by a hecatomb of the whitest oxen with gilded horns entwined with flowers; next were chariots, laden with the spoils of the vanquished; and after them, long ranks of chained captives conducted by files of lictors. Then came the conqueror, clothed in purple and crowned with laurel, having an ivory sceptre in his hand; a band of children followed dressed in white, who threw perfumes from silver censors, while they chanted the hymns of victory and the praises of the conqueror. The march was closed by the victorious troops, with their weapons wreathed with laurel; the procession marched to the temple of Jupiter, where the victor descended and dedicated his spoils to the gods.