When soldiers were to be raised from the allied cities of Italy, notice appears to have been sent by the consuls to the magistrates of those cities, who then enrolled men in a manner similar to that which was practised at Rome ; and, having caused them to be disciplined, sent them to join the army.
On the institution of regular bodies of troops by Romulus, he Is said to have divided them (probably each legion) into companies of 100 men, and these were called Manipuli, from the bundles of grass which served as standards for the people who accompanied him when be attacked the palace of Amtdius. (Aur. Victor, ' Origo Oen. Rom.; c. 22.) The first mention of a cohort occurs shortly after the expulsion of the kings (Liv., ii. 11); and in the time of Polyblus the legion was divided into ten cohorts, each of these into three manipuli (Polyb., b. xi.), and each of the latter into two centurire. [Collins.] A manipulus must have then consisted of 200 men ; and at a latesperiod it designated a body of less than the original number. Two Cenlurioncs were appointed under each Manipulus : each C'enterione had under him two Sub Ccnturionts, and a standard-bearer (Si:,nifer). Beneath these were tho Decurioncs. Under Hadrian and the emperors immediately following him the cohorts appear to have been of unequal strength. Vegetius states that the first, which was called cohort milliaria, and which carried the eagle, Consisted of 1500 foot and 132 horsemen ; the second, called cohors quingenario, of 555 foot and 70 horsemen ; and that the re maining cohorts were nearly of the same strength as the second.
Servius Tullius is said to have divided the military force into five different classes of troops (Liv., i. 43), which were distinguished by their armour ; but from the commencement of the republic, or nearly so, the order of battle consisted of three lines of troops, the Ilaatait, the Principes, and the Triarii (Liv., viii. 8.) The Velars (light troops or skirmishers) had no particular station, and except the latter, all the troops, according to Polybitis, were armed nearly in the same manner.
The youngest men were selected to act as velitcs : they were armed with bows or slings, and some of them carried a light javelin. After the time of Marius ceased to be enrolled as legionary troops, and were chiefly foreigners. Vegetius designates them Ferentarii. They wore short swords, and were provided with bucklers of a circular form, about three feet in diameter. The staff of their javelin was two cubits
long, and as thick only as a finger ; the iron head tapered gradually to a fine point, in order that, being bent at the first discharge, it might be rendered useless to the enemy.
The hastati of all the cohorts were stationed in the first line; the principes formed the second, those of each cohort supporting their own hastati; and the triarii were similarly disposed in the third lino to support the principes. All the three classes were completely armed with cuirass, helmet, and greaves; their buckler was 4 feet long and 2i feet broad, and five arrows were placed in its concavity, to be thrown when necessary. Each man was provided with a long and a abort sword, the blade of the former being strong, and made either to cut or thrust ; and he carried, besides, two javelins, or pile. (Pulyb., b. vi.) The only difference In the arms of the three classes seems to have con sisted in the size of the pilum, those used by the triarli, or veteran soldiers, in the time of Varro being longer and heavier than those of the men in the other lines.
It is supposed that originally the principes were stationed in the first line, and that they were men of the superior classes; from which circumstance, or because they came first into action, they may have their designation. he front of the legion, when in order of battle, was formed by ten corps of the hastati, each corps being arranged with 10 men in front, and 10 in depth. The second line, or that of the principes, was of the same strength, and was drawn up in the same manner. The line of triarii consisted also of ten corps; but these had only 10 men in front and G in depth. Every legionary soldier was allowed five feet in front, and as much in depth, in order that ho might be enabled to make free use of his arms.
The cavalry of a Roman legion was divided into ten lurmw, of about 30 horsemen each, who, in order of battle, were drawn up with 8 in front, and 4 in depth. Each legion of the allies had however GOO horsemen ; so that the cavalry of a consular army (consisting of two Roman legions and two legions of allies) amounted to 1800 men, who were disposed on the wings of the legion, in one line or two, according to circumstances. The legionary cavalry were furnished with cuirasses and helmets, and they were accompanied by light-armed horsemen, who served nu archers.