itself deserves attention, and, as it chances, we know much about it, mainly from Polybius. Its elements were three:—
(A) The principal unit was the legion, generally a division of 4500 men—3000 heavy infantry, 1200 lighter-armed (velites), 300 horse—though sometimes including as many as 6000 men. The heavy infantry were the backbone of the legion. They were levied from the whole body of Roman citizens who had some private means and who had not already served 16 campaigns, and in effect formed a yeoman force, For battle they were divided into 1200 hastati, 1200 principes and 600 triarii; all had a large shield, metal helmet, leather cuirass, short Spanish thrusting and cutting sword, and in addition the hastati and principes each carried two short heavy throwing spears (pila), while the triarii had ordinary long spears (see Arms and Armour). They were drawn up in three lines: (1) hastati, (2) principes, (3) triarii; the first two were divided into 10 maniples each (of 120 men, when the legion only counted 4500), the third into 10 maniples of half the strength. According to the ordinary interpretation of our ancient authorities, the maniples were arranged, in a chess-board fashion (quincunx), the idea being that the front row of maniples could retire through the intervals in the second row without disordering it, and the second row could similarly advance.
| 1 | 1 | 1 | ||||
| Hastati | . | |||||
| 1 | 1 | |||||
| Principes | . | |||||
| 1 | 1 | 1 | ||||
| Triarii | . |
Recent military writers, however, doubt whether this arrangement can be considered workable, and it is possible that our authorities did not really mean what has been supposed. In any case the procedure in fighting seems to have been simple: the front line discharged a volley of pila and rushed in with the short sword—a sequence much like the volley and bayonet charge of the 18th century—and if this failed, the second line went in turn through the same process: the third line of triarii, armed with spear instead of pilum, was a reserve. The velites, armed with javelins, were either broken up among the heavy-armed centuries or used as skirmishers or as aids to the cavalry. The 300 cavalry, however, were (it seems) of little account—a natural result if, as we have reason to think, the horses were small and stirrups were not used. The officers of the legion consisted of: (a) Six tribunes, in part elected by the comitia, in part appointed by the consuls, and holding command in rotation. They were either veteran officers, sometimes even ex-magistrates, or young noblemen beginning their career. (b) Sixty centurions, each commanding one century, or, rather, a pair commanding each maniple. They were chosen by the tribunes from among the veteran soldiers serving at the time and were arranged in a complicated hierarchy, by means of which a centurion might move upwards till he became primus pilus, senior centurion of the first maniple of triarii, the chief officer in the legion. (c) There were also standard-bearers and other under-officers, for whom reference must be made to specialist publications.
(B) Besides the legions, composed of citizens, the Roman army included contingents from the Italian “allies” (socii), subjects of Rome. These contingents appear to have been large: in many armies we find as many socii as legionaries, but we are ignorant of details. The men were armed and drilled like the legionaries, but they served not in legions but in cohorts, smaller units of 400-500 men, and their conventional positions seem to have been on the wings of the legions. They were principally infantry, but included also a fairly large proportion of cavalry. Despite their numbers, they do not appear to have ranked with the heavy legionary infantry, and they were probably used more as detachments from the main army than as infantry of the line.
(C) Besides legionaries and socii, the Roman army included non-Italian troops of special kinds, Balearic slingers, Numidian horsemen, Rhodians, Celtiberians and others: at Trasimene, for example (217 B.C.), the Roman army included 600 Cretan archers. The numbers of these auxilia varied; probably they were not numerous till the latest days of the Republic.
Composition and Size of Armies in the Second Stage.—According to the general practice, each of the two consuls, if he took the field alone, commanded an army of two legions with appropriate socii. If the two consuls combined their forces, commanding the joint force in rotation (as often occurred), the total would be—according to our authorities—four legions, each of 4200 infantry, the same number of “allied” infantry (in all 33,600 infantry), 1200 legionary cavalry and about 3600 “allied” cavalry = 38,400 men. Such, for example, was the Roman army at Trebia (218 B.C.), where (says Polybius) there fought 16,000 legionaries and 20,000 allied infantry. The total number of men in the field could be increased; we even hear of 23 legions serving at one time in the Second Punic War. Just before this war, in 225 B.C., the total strength of Rome was reckoned at three-quarters of a million, of which about 65,000 were in the field and 55,000 were in a reserve at Rome; of the total, 325,000 were Roman citizens and 443,000 (apparently a rough estimate) were allies. The battle order in normal circumstances was simple. In the centre stood the legionary infantry: on each side of that was the allied infantry: on the wings the cavalry. But sometimes the legions were held in reserve and the brunt (and honour) of the fight was left to the allies. Sometimes, when the army was a double force, one commander's troops fought and the others lay in reserve. Frequently the attack was begun by one wing, as by Caesar at Pharsalus. At Ilipa in Spain Scipio put his Spanish auxiliaries in the centre, his Roman troops on the wings, and attacked with both wings. The chief command of the army fell (as stated above) to the consul, if present, or, if two consuls acted together, to them in turn. In default of consuls, a proconsul, praetor, or propraetor, in charge of a province, would command.
Development from the Second Stage to the Third.—Towards the end of the Republic many changes began to work themselves out in the Roman army. If Camillus began the system of pay and long service, it was effectually developed by long foreign wars in Spain and in the East. Moreover, the growth of Rome as a wealthy state tended to wreck the old theory that every citizen was a soldier, and favoured a division of labour between (e.g.) the merchant and the military, while the increasing complexity of war required a longer training and a more professional soldier. In consequence, the old restriction of legionary service to men with some sort of private property was abolished by Marius about 104 B.C. and the legionaries now became wholly proletariat and professionals. By a second change, also connected with the name of Marius, the legion was reorganized as a body of 6000 men in 60 centuries, divided into 10 cohorts instead of (as hitherto) into 30 maniples; the unit of tactical action thus became a body of 600 instead of 120. This was probably an adaptation within the legion of the system of cohorts already in use for the contingents of the socii. Soon after, the extension of the Roman franchise to all Italians converted allies and subjects into citizens, and the socii into legionaries. A fourth change abolished the legionary cavalry and greatly increased the auxilia (C above). And, finally, the appearance of great military leaders in place of civilian statesmen, and of pretenders to a throne in place of patriots, familiarized the world with the notion of large standing armies commanded by permanent chiefs, and at the same time destroyed discipline and military loyalty.
Third Stage.—The Imperial Army of Defence.—The evils of the Civil Wars (49-31 B.C.) furnished the first emperor, Augustus, with both the opportunity and the necessity for reforming the army. Disorganization had reigned for twenty years. It was needful to restore loyalty and system alike. Augustus did this, as he did all his work, by adapting the past: yet there is some truth in the view of his latest historian, von Domaszewski, that his army reforms were his greatest and most original work. The main lines of his work are simple. The Imperial army consisted henceforward of two classes or grades of troops, about equal in numbers if unequal in importance. The first grade were the legions, recruited from Roman citizens, whether resident in Italy or in the provinces. The second grade was formed by the auxilia, recruited from the subjects (not the citizens) of the Empire in the provinces, organized in cohorts and alae and corresponding somewhat to both the socii and the auxiliaries (B, C above) of the Republican army. There were also in Rome special “household” troops (see Praetorians); and a large body of vigiles who were both fire brigade and police.
(A) The legion of the Empire was what Marius had left it—6000 heavy infantry divided into 10 cohorts: Augustus added only 120 horsemen to serve as despatch-riders and the like. The supreme command was no longer in the hands of the six tribunes. According to a practice which had sprung up in the latest Republic it was in the hands of a legatus legionis, deputy of the general (now of the emperor, commander-in-chief of the whole army) and a man usually of senatorial rank and position. The six tribunes assisted him, in theory: in practice they were now little more than young men of good birth learning their business or wasting their
