I. Composition of the Army
1. The legion. The strength of the Roman army lay in the legions (legiones). These in Caesar's time were composed exclusively of Roman citizens, brought into the service by means of levies (dilectus), which were now held in other parts of Italy as well as in Rome. Conscription was no longer limited to the higher classes, and those who had means could employ substitutes; probably the legionary soldiers (legionarii milites, or simply milites) or Caesar were mainly volunteers, who were willing to enlist for the regular term of twenty years on account of the certainty of the pay, and of provision for their old age in case they lived beyond the period of service. Citizens were liable to be called out at any time between the ages of seventeen and forty-six; Romans of the upper classes who wished to serve in the army, or found themselves unable to evade conscription, were employed as officers, or attached to the bodyguard of the commander. The kind of recruit considered desirable is thus described, in a rule for muster-officers (Veg. i. 6): "The young man who is to be accounted fit for the business of war ought to have a quick eye, straight neck, broad chest, muscular shoulders, powerful arms, rather long fingers, and a lithe person; the calves of his legs and his feet should be hard and sinewy rather than plump. When you find a recruit with these points, don't trouble about height; it is better to have brave soldiers than big soldiers."
The number of men in a legion varied according to circumstances; for the killed or disabled were not replaced by recruits enrolled in the same legion, but when an accession of strength was received, either new legions were formed, or the recruits were placed in a separate corps. The longer a legion remained in service the smaller it became. The normal strength of a legion at the end of the Republic was 6000 men; but the average number of men in Caesar's legions probably did not exceed 3600. When Caesar was going to meet Ariovistus he took all the horses of the Gallic cavalry and mounted on them the soldiers of the tenth legion (Bel. Gal. I. xlii). As the Gallic cavalry numbered 4000 (Bel. Gal. I. xv), and the context shows that the whole, not a part, of the tenth legion was taken, after the battle of the Helvetii, this legion had not more than 4000 men. In the fifth year of the war we find two legions averaging barely 3500 men each (Bel. Gal. V. xlviii, xlix). At the battle of Pharsalus the 80 cohorts in the line of battle numbered only 22,000 men, an average of 2750 to a legion; the total effective force of two legions a little later is reported as 3200, or 1600 men apiece (Bel. Civ. iii. 89, 106). The legion was divided into ten cohorts (cohortes), averaging, in Caesar's army, about 360 men each; the cohort was divided into three maniples (manipuli) of 120 men; the maniples into two centuries (ordines). In legions having a full complement of men each century would contain 100; in Caesar's army the number could hardly have averaged more than 60.
The legions that had seen long service (apparently not less than nine or ten years; cf. Bel. Gal. viii. 8) were called 'veteran' (legiones veteranae); the rest, 'last levied,' or raw (legiones proxime conscriptae, or legiones tironum). The different legions were designated by number. In the first year of the Gallic War Caesar had four veteran legions, numbered VII., VIII., IX. (these three apparently brought form the vicinity of Aquileia; (Bel. Gal. I. x.), and X., the last mentioned having been in 'the Province' at the time of his arrival (I. 7. 5); after he learned that the Helvetians proposed to go through the country of the Sequani and the Aedui, he hastily raised two legions in Cisalpine Gaul (I. x. 9), which were numbered XI. and XII. With these six legions he gained two of his most brilliant victories, over the Helvetians and over Ariovistus. In the second year of the war he raised two new legions in Cisalpine Gaul, numbered XIII. and XIV., so that he now had four veteran and four raw legions, eight in all. In the fifth year (B.C. 54) the XIVth legion and half of another were annihilated in the ambuscade set by Ambiorix (V. 26-37). At the beginning of the next year Caesar raised two more legions in Cisalpine Gaul, one replacing the lost XIVth, the other numbered XV., and besides obtained a veteran legion from Pompey, which was numbered I. (vi. 1; viii. 54). In the last two years of the war he had thus ten legions, numbered I., and VII. to XV. inclusive, besides a separate corps (supplementum), the size of which is not given. It appears probable that the whole force of legionary soldiers engaged in the siege of Alesia fell short of forty thousand.
2. The infantry auxiliaries. Besides the legions, a Roman army contained bodies of infantry and cavalry drawn from allied and subject peoples, or hired outright from independent nations (auxilia). These in some cases retained their native dress, equipment and mode of fighting, in others were armed and trained after the Roman fashion. To the former class belong the light-armed troops (milites levis armaturae), including especially the slingers and bowmen. In the Gallic War Caesar availed himself of the help of slingers from the Balearic Islands (II. vii. 3), bowmen from Crete and from Numidia (II. vii. 2), and light-armed German troops (VII, xlv., 12). He utilized also contingents from Illyricum (V. i. 17-18) and from the Gallic States that he subdued (viii. 10). In 52 B.C. he had a force of ten thousand Aeduans (VII. xxxiv. 1-6). Caesar, as other Roman writers, is generally not careful to state the exact number of the auxiliary troops; they were regarded as relatively unimportant. The officers of the auxiliaries, both infantry and cavalry, were Romans.
3. The cavalry. In the earlier organization of the Roman army a troop of cavalry accompanied each legion. While the evidence is not conclusive, it is probable that in the latter part of the Gallic War, if not from the beginning, Caesar had contingents of cavalry in connection with his legions, averaging 200 to 300 men each. These horsemen were foreigners, serving for pay; they were drawn from Spain, from Germany, and from Gaul. Apart from the legionary contingents, Caesar had a force of cavalry raised from the Gallic States subject or friendly to Rome, which was reckoned as a single body, numbering under ordinary circumstances about 4000 men. This force in the fall would separate, each part returning to the state from which it came; in the spring it would be assembled again for the campaign. The contingents serving with the legions probably remained with them both winter and summer; they received only passing reference in the narrative perhaps because Caesar assumed that the arrangement was familiar to his readers.
The cavalry was divided into squads (turmae), of about 30 horsemen; such a squad went with Commius to Britain (IV. xxxv. 3-5). Probably the squad contained three decuries (decuriae), of 10 men each, under the command of decurions (decuriones). The higher officers were called cavalry prefects (praefecti equitum).
4. The non-combatants. Of these there were two classes, slaves employed for menial services, and free men, or freedmen. In the former class were included the officers' servants and tent-servants (calones), as well as the drivers and the muleteers with the heavy baggage (muliones); to the latter, citizens or others who were allowed to accompany the army but were obliged to find quarters outside of the camp, as the traders (mercatores; cf. VI. xxxvii. 5-6), and the camp-followers (lixae, not mentioned by Caesar).
Artisans (fabri) were not enrolled as a separate corps, but were drawn from the ranks of the legionary soldiers whenever needed.
5. The baggage-train. The heavy baggage (impedimenta) comprised tents, hand-mills for grinding grain, artillery, extra weapons, and other military stores, as well as supplies of food. Each legion had a separate baggage-train. When accompanied by this on the march it was called 'encumbered' (legio impedita); when without the baggage, 'unencumbered' (expedita). From the baggage of the legion, or heavy baggage, the baggage of the soldiers, carried in individual packs (sarcinae), should be carefully distinguished.
II. The Officers
Next in rank came the lieutenants (legati), who were frequently placed by Caesar in command of separate legions, or of corps containing more than one legion. When acting in the absence of the general the lieutenant became 'lieutenant in the general's place' (legatus pro praetore), and exercised unusual authority. The quaestor was properly charged with the care of the military chest and the supplies, but was sometimes clothed with purely military authority, and assumed the functions of a lieutenant. The quaestor and the lieutenants belonged to the staff of the general, and had with him the distinction of a body-guard (cohors praetoria), composed of picked soldiers and of young men of rank who wished to acquire military experience.
The military tribunes (tribuni militum) numbered six to a legion. In earlier times these officers commanded the legion in turn. In Caesar's army they appear to have received appointment for personal rather than military reasons (cf. I. xxxix. 8-18); as the command of the legions had been given over to the lieutenants, the military tribunes were intrusted with subordinate services, such as the leading of troops on the march, the command of detachments smaller than a legion, the securing of supplies, and the oversight of the watches. Only one military tribune (Gaius Volusenus), is mentioned by Caesar in terms of praise.
In marked contrast with the higher officers, who were of good social position, were the captains, or centurions (centuriones, ordines). These were often of the humblest origin; they had been promoted from the ranks simply on account of bravery and military efficiency. At the drill, on the march, and in battle, they were at the same time the models and the leaders of the soldiers. As each century had a centurion, there were 60 in the legion. The first in rank was the first centurion of the first cohort (primipilus); but how the other centurions stood related in respect to authority, and what the order of promotion was, from present evidence it is impossible to determine.
Below the centurions, but ranking above the common soldiers, were the privileged soldiers, who were relieved from picket-duty as well as work on fortifications and other manual labor. Such were the veteran volunteers (evocati), soldiers who had served their full time but had re-enlisted at the general's request; the orderlies (beneficiarii), who performed various services for the higher officers; the adjutants (optiones), or substitutes chosen by the centurions; the musicians, and the standard-bearers.
III. Provisioning and Pay of the Soldiers
Caesar took every precaution to have ample supplies always at hand. The care of the stores was in the hands of the quaestor, with his staff. Not bread or flour, but grain (frumentum), usually wheat, was served out to the soldiers for rations. This they themselves ground with hand-mills (molae manuales) and prepared for food, by boiling into a paste or by making into bread without yeast. The grain was portioned out every fifteen days, and on the march each soldier carried his share in a sack. The amount furnished does not seem large when we reflect that the men lived almost exclusively on a vegetable diet. The allowance for the fifteen days was two Roman pecks (modii), about half a bushel by our measure. As the weight of this was not far from thirty pounds, the soldier had about two pounds per day. On difficult or forced marches extra rations were served out. If the soldier desired to do so he could trade off his grain for bread, or buy other articles of food from the numerous traders (mercatores), who accompanied the army and had a flourishing business. When wheat was scarce, barley (hordeum) was substituted. Rations of barley were frequently served out also as a punishment for slight offences. In traversing an enemy's country fresh meat was often secured.
Previous to Caesar's time the pay (stipendium) of the legionary soldier was 120 denarii per year, which amounted to about 6 cents per day; the centurion received twice as much. At the beginning of the Civil War Caesar doubled this, so that the soldiers received (under the new coinage) 225 denarii a year, or about 12 cents per day, the centurion 25 cents, not far from $46 and $92 per year respectively. Out of this sum the soldier had to provide for his own clothing and equipment, and other expenditures; but the purchasing power was much greater than that of an equivalent amount today.
In successful campaigns soldiers had a share of the booty (praeda), consisting largely of captives, who were sold as slaves (cf. VII. lxxxix. 9-11). These were bought up on the spot by the traders, and thus readily turned into cash. Sometimes Caesar gave money realized from the sale of booty (praemium); thus after the conquest of the Bituriges in 51 B.C. the soldiers received 200 sesterces (about $8.00) apiece, the centurions a much larger sum (Bel. Gal. viii. 4). As other rewards (praemia), the commander could make special gifts (dona), such as the familiar disk-shaped decorations of metal, for the breast (phalerae); chains (torques); rings for the arms (armillae); little silver or gold spears (hastae purae) or shields (parmae purae); and sacrificial bowls (paterae sacrificiales).
At the close of his period of service (twenty years), or on reaching his fiftieth year, the soldier who had served well was entitled to an honorable discharge (missio honesta), together with an allotment of land, or a payment of money, which under the Empire amounted to 3000 denarii. When released on account of health or disablement he received an invalid's discharge (missio causaria). The general sometimes granted a discharge by favor (missio gratiosa). When convicted of cowardly or disgraceful conduct the soldier was deprived of his weapons and driven from the camp, or in extreme cases put to death.
Regarding the pay of the higher officers and the auxiliaries definite information is not at hand.
IV. Dress and Equipment
The legionary soldier wore a thick woolen undergarment reaching nearly to the knees (tunica). His cloak (sagum), which served also as a blanket, was likewise of undyed wool, and fastened by a clasp (fibula) on the right shoulder, so as not to impede the movement of the right arm. The soldier's half-boots (caligae) were much like a sandal, with heavy soles, held on by straps over the ankle. A uniform in the modern sense was unknown in antiquity. The cloak of the commander (paludamentum) differed from that of the soldier only in being more ample, of finer quality, and ornamented; it was ordinarily scarlet in color (cf. VII. lxxxviii. 1-2), and often fringed.
The weapons were of two kinds, defensive and offensive. As defensive weapons, the legionary soldier had:
1. A helmet of metal (cassis or galea), ornamented with a crest (crista).
2. A cuirass, or coat of mail (lorica) of leather or of leather strengthened with strips of metal, or of metal, very strong and heavy.
3. A shield, ordinarily rectangular (scutum), but in some cases probably oval (clipeus), made of two layers of boards fastened together, strengthened on the outside by layers of linen and of leather, and at the edged by a rim of metal. At the middle of the outside was an iron knob (umbo), used in striking, from which extended strips of metal in a form suggestive of thunderbolts. On the march the shield was protected from the wet by a leather covering. In battle it was held on the left arm.
His offensive weapons were:
1. A pike (pilum), a heavy and formidable javelin. It consisted of a square shaft of wood four feet long, into the end of which was carefully fitted a long iron point, suggestive of a bayonet, projecting two feet beyond the end of the wood. The weight of the whole was not far from ten or eleven pounds, about the same as that of the guns furnished by modern nations to their infantry. Pikes could be thrown only about 75 feet; but they were sent with such skill and force that the first hurling often decided the battle.
2. A sword, called 'Spanish' (gladius Hispanus) because made according to a pattern brought from Spain after the Second Punic War. The 'Spanish sword' was short, broad, two-edged and pointed, better adapted for stabbing than for slashing, though used for both purposes. It was kept in scabbard (vagina) fastened to a belt (balteus), which was not passed around the waist, as our soldiers have it, but over the left shoulder; this brought the sword on the right side, so that it was not in the way of the shield. In the time of the Empire, and perhaps also in Caesar's day, soldiers had a dagger (pugio) also, worn on the left side, attached to a belt running around the waist.
The dress and equipment of the light-armed soldiers varied greatly, and our information on many points is incomplete. They, as well as the cavalry, seem generally to have had a round shield, about three feet in diameter (parma). The cavalry had light lances, or darts, for hurling (tragulae, tela), and longer sword than that used by the infantry.
V. The Standards and Musical Instruments
The movements of the Roman army were directed largely by means of ensigns and of signals given on wind-instruments. While the ancient battle lacked the roar and smoke of cannon and of smaller arms characteristic of modern engagements, great clouds of dust were raised and obscured the movements of the combatants; the standards were more numerous and had a relatively more important place than the flags of today.
The ensigns of Caesar's army were:
1. The legion-eagle (aquila) of silver, carried in battle on the end of a pole, and entrusted to the especial care of the first centurion (primipilus). In camp it was kept in a little (sacellum). It was the standard of the legion as a whole; the eagle with extended wings borne aloft seemed to signify that the bird sacred to Jupiter, god of victory, was ready to lead the legion to victory; and the loss of the eagle was the deepest disgrace that could be incurred. The bearer of the eagle was called aquilifer. The ancient Persians had a golden eagle as the royal standard; and today the eagle holds an important place among the military emblems of Austria, Russia, Germany, France, and the United States.
2. The standards (signa), one to each maniple. These seem to have manifested a considerable variety of detail. One type, known from a coin struck in 49 B.C., had small streamers attached to the end of the pole, underneath which were two half-moons (probably for good-luck), one just above the other; below these were two disks of metal (phalerae), no doubt presented to the maniple for meritorious conduct, and last of all a square piece of cloth (vexillum), indicating by a letter the place of the maniple. The order of the decorations on the staff varied; and the place of the half-moons was in other cases apparently taken by figures of animals. In later times at any rate the vexillum might be replaced by a plate of metal. There was no separate standard for the cohort.
3. The banners (vexilla), rectangular flags of different sizes used for a variety of purposes. A large red vexillum was the special ensign of the general (cf. II. xx. 1-2). Smaller banners were used by special detachments not formed of regular maniples (cf. VI. xxxvi. 14-19), or attached to the standards of the maniples.
The musical instruments were:
1. The trumpet (tuba), about three feet long, with a funnel-shaped opening; it had a deep tone.
2. The horn (cornu), a large curved instrument, with shriller note.
3. The shell-horn (bucina), an instrument having a slight resemblance to the large shells still in use about
Naples as dinner-horns; it had a hoarse tone, apparently of a higher pitch than that of the trumpet, and was used especially in camp for giving the signals to change the watches.
As the maniple was the unit of military movement, signals were addressed to the standard-bearers (signiferi). The order "to advance" or "to retreat" was conveyed by the general to the trumpeters (tubicines; cf. II. xx. 3; VII. xlvii. 1-3); their signal was taken by the horn-blowers (cornicines), of whom there was one to each maniple. The notes of the instruments could be heard above the din of battle much more clearly than the orders of the officers.
On the march the standard was at the front, in battle near the rear, of the maniple. From the immediate association of the manipular standards with military movements arose several idiomatic expressions. Such are: signa inferre, 'to advance;' signa referre, 'to retreat;' signa convertere, 'to face about;' signa efferre, 'to leave camp;' ad signa convenire, 'to assemble.'
VI. The Army on the March
Great attention was paid by Roman generals to the order and discipline of the march; but Caesar made his marches a strategic element of prime importance in determining the issues of the war.
The army advanced ordinarily in three divisions. At the front (primum agmen) came the cavalry, with perhaps a division of light-armed troops (cf. II. xix. 8-9), sent ahead to spy out the country, and in case of meeting an enemy, hold him at bay until the rest of the army could prepare for action (cf. e.g., I. xv. 1-4). Next came the main force, the arrangement of which varied according to circumstances; for while ordinarily each legion was accompanied by its baggage-train, when there was danger of attack the legions marched in single colum, with the baggage of the whole army united; on rare occasions the force advanced in battle order, but we are to understand by this (except in one instance of a short advance, I. xlix. 3-5) that the legions marched not in line of battle, but in a column that could be formed into a line of battle on a moment's notice. When marching in battle order the individual soldier was without his baggage (sarcinae), which under all other circumstances he was obliged to carry; before the engagement with the Helvetii, though Caesar had been marching in close proximity to the enemy, the packs had to be laid off before the soldiers could prepare for battle (I. xxiv. 6).
The rear (novissimum agmen) might in case of danger be formed of one-fourth of the legionary force, the baggage being between the rear and the main body (cf. II. xix. 3-7; VI. viii. 3 et seq.).
The regular day's march (iustum iter) was from six to seven hours long. The start was usually made at sunrise; but in special emergencies the army got under way at midnight, or two or three o'clock in the morning. The distance ordinarily traversed was about 16 English miles; on forced marches (itinera magna) much greater distances were made, as 25 or 30 English miles. Caesar's forced marches were many in number, and manifested astonishing powers of endurance on the part of his soldiers. Rivers were crossed by means of bridges, either permanent or hastily constructed, and by fording; an ancient army could pass a deeper ford than the armies of today, because there was no ammunition that would be spoiled by the water.
On the march the soldier carried, besides his food supply, his cooking utensils (vasa), his arms, blanket, and one or two rampart stakes (valli). The luggage was done up in a tight bundle (sarcinae), which was fastened to a forked pole, and thus raised over the shoulder. This arrangement was introduced by Marius, in memory of whom soldiers so equipped were called "mules of Marius" (muli Mariani). The helmet was hung by a cord from the neck, the other weapons disposed of in the most convenient way. When it rained, the oblong shields (scuta) could be put over the head like a roof. The entire weight of each legionary soldier's burden must have been at times as much as sixty pounds, --and still more than this when, on special service, rations were served out for an unusual period. The infantry of our day are not expected to carry more than forty or forty-five pounds apiece. When preparing for battle the legionary soldiers freed themselves from their luggage, either leaving it in camp or depositing it in heaps in a guarded place.
VII. The Army in Camp
The Roman camp was laid out, fortified, and guarded with great care. Even when the army was to remain in a place but a single night the same precautions were ordinarily taken as if a stay of weeks was intended. When the army was on the march, men were sent forward to choose a suitable location for a camp and measure it off (castra metari; the surveyors were called castrorum metatores or mensores). Whenever possible, a site was selected on a slight elevation (locus superior), with abundance of water and of wood for fuel near at hand. The proximity of a dense forest or overhanging mountain was avoided, that a favorable opportunity of attack might not be given to the enemy. When possible, the rear or one side was placed parallel with a river (cf. II. v. 15-20).
The camp was usually square or oblong; in a few cases there were camps of other shapes, adapted to the nature of the ground. The size of the camp varied according to the size of the force; but it might be made smaller than usual on account of the absense of baggage (IV. xxx. 4-6) or for strategic reasons (V. xlix. 15-20).
First an embankment was thrown up on all sides. Outside of this was a trench, from which the earth for the embankment was taken. On the outer edge of the embankment a row of strong stakes or palisades (valli) was driven firmly in. The rampart thus made (vallum) was several feet high and wide enough for the soldiers to stand on behind the palisades. The ditch (fossa) was from twelve to eighteen feet wide (cf. II. v. 21-23), and from seven to ten feet deep. When the army expected to remain in the same place for a long time (castra hiberna, castra stativa), sometimes watch-towers were added at certain intervals, and the intervening spaces further protected by a roof. the labor of fortifying a camp was prodigious; the ease and quickness with which the work was done are a further evidence of the endurance of the Roman soldiers. The system was in every way productive of the best results. It lessened greatly the chances of successful night attacks by the enemy; and it made the army more independent, ready to stand wholly on the defensive if need be. Modern generals are returning in this respect to the Roman tactics; while in the enemy's country they rarely pass a night without throwing up breastworks and making use of whatever means of fortifying may be at hand. In our recent War for the Union not infrequently barrels or hogsheads filled with earth took the place of the Roman rampart.
The camp had four gates. That in the direction of the advance, toward the enemy, was called the porta praetoria; the one opposite to this, at the rear, porta decumana; those on the right and left side respectively, as one faced the front, porta principalis dextra and porta principalis sinistra. The last two were connected by the chief street (via principalis). Inside the rampart, between it and the tents, a vacant space two hundred feet wide was left on all sides. The remaining room in the enclosure was systematically divided, so that every maniple, decuria, and body of light-armed troops knew its place and could find its quarters at once; but the details of the arrangement in Caesar's time are not known.
The tents were of leather. Each was calculated to hold ten men; but a centurion seems generally to have had more room to himself than the soldiers. In a hostile region a strong guard was always kept before the gates; and the entrances were made more easily defensible by an approach so arranged that an enemy attempting to enter would expose the right side, unprotected by a shield.
The night, from sunset to sunrise, was divided into four watches (vigiliae), numbered prima, ending at 9 o'clock; secunda, ending at midnight; tertia, from midnight to 3 A.M.; and quarta, from 3 o'clock to sunrise. In the earlier times, and probably in Caesar's army, the password of the sentinels, different each night, was written on slips of wood, which were given by the commander to the military tribunes, and passed by these to the men on duty.
The winter-quarters (hiberna, or castra hiberna) were made more comfortable than the ordinary encampments, by the substitution of straw-thatched huts (casae, V. xliii. 2-5) for tents. Many Roman camps became the nucleus of permant settlements, which exist still in cities of today. In several towns which originated thus the plan of the Roman camp can be clearly seen in the arrangement of streets and the surrounding wall. A marked instance is the city of Chester, England, the name of which is derived from castra; so Rochester comes from Rodolphi castra, and all names of English towns ending in -chester point to Roman encampments.
VIII. The Army in Battle Array
When the Roman force was far outnumbered by the enemy, the legionary soldiers were arranged in a double line (duplex acies; III. xxiv. 1-3), or even in a single line (simplex acies), as at the battle of Ruspina (Bel. Afr. 13). Under ordinary circumstances Caesar drew up his legions in a triple line (triplex acies), as in the battles with the Helvetii, Ariovistus, and the Usipetes and Tencteri; probably also in the batle with the Belgae and the Nervii. Exactly what this arrangement was cannot be determined. Evidence has been accumulated against the view, formerly current, that intervals were left in the first line of the triplex acies through which the maniples or cohorts of the second line could advance to relieve the first. The explanation which seems on the whole freest from objection is this:
Four cohorts of each legions stood in the first line; about 160 feet behind them stood three cohorts, the remaining three cohorts of the legion being posted farther back as a reserve. The three maniples of each cohort stood side by side, one of the centuries in each maniple being behind the other. On the assumption that a legion contained the full quota of 6000 men, the first line of the triplex acies would have 2400 men, standing in 4 cohorts, or 12 maniples, 10 ranks deep; the second and third lines would each have 1800 men in 9 maniples of the same depth. The first rank of the legion would thus contain 240 men, and extend about 720 feet; by leaving intervals between legions six legions might be formed in a triple line of battle a mile or a mile and a half long. If a legion were of less than the normal size, the depth or front, perhaps both, would be correspondingly reduced; there is some reason for supposing that in Caesar's army the men stood 8 ranks deep. The soldiers in each battle-line stood about three feet apart each way. As the first line went into action the second followed closely behind; as the men of the first fell or withdrew exhausted, those of the second pressed forward and took their places; in case of need the third line advanced and in like manner relieved the combined first and second. At the batle with the Helvetii the whole third line faced about and repelled an attack on the rear.
When circumstances required it, soldiers were massed in serried ranks, as in a wedge-shaped column or under a tortoise-cover (testudo). For defence sometimes a force was formed into a circle, corresponding with our hollow square (cf. IV. xxxvii. 6-14; V. xxxiii. 9-17).
The place of the light-armed troops and cavalry was ordinarily at first in front of the triplex acies, or on the wings. They opened the engagement by skirmishing, prevented flank movements of the enemy, drew the brunt of the attack if the legions wished to take another position, and were employed in various other ways as occasion demanded. The cavalry were utilized especially to cut down the fleeing.
IX. Operations Against Fortified Places
The taking of walled towns was accomplished either by sudden storming without long preparation (repentina oppugnatio); by siege-blockade (obsidio, VII. lxix. 3; obsessio, VII. xxxvi. 5), which aimed to repel all attempts of the enemy to escape, and to reduce him by starvation, as at Alesia (VII. lxix-xc); or by siege (longinqua oppugnatio), with the help of appliances to break down the enemy's fortifications and gain admission to the city, as at Avaricum (VII. xvi-xxxii). In storming a city (expugnatio) the forces rushed forward, tried to batter down the gates, fill up the moat (fossas complere), and mount the walls with ladders (scalae), endeavoring in every way to get into the place. The siege was commonly a work of weeks or of months. After the enemy had been so weakened that an attack would probably reduce him, and after the preparations were completed, a final assault was made.
The siege was begun by extending a line of works (circumvallatio), in case the nature of the site allowed, entirely around the place to be reduced. Then a 'mole,' a high and wide mound of timber and earth (agger) was begun just outside the reach of the enemy's weapons, gradually prolonged toward the city wall, and raised until at the front the top was on a level with the wall, or even higher. In the mole there were passage-ways through which the materials for the structure could be safely carried.
The workmen at the front were protected by movable breast-works (plutei), or by arbor-sheds (vineae), made of timber or of thick wickerwork, with raw-hides stretched over the outside as a protection against fire. Rows of arbor-sheds were placed along the sides of the mole to afford passage-ways to the front. Movable towers (turres ambulatoriae), filled with soldiers, were brought up near the walls. The highest tower mentioned in the narrative of the Gallic War was of ten stories (VIII. xli). In the lowest story of the movable tower, or under a separate roof, was the battering-ram (aries), an enormous beam with a metallic head swung against the walls with terrific force.
For throwing heavy missiles the Romans had several kinds of artillery, called 'torsion-hurlers' (tormenta). Of these the most important were:
a. The catapult (catapulta) for shooting large arrows or darts. A small catapult is called 'scorpion' by Caesar (scorpio, VII. xxv).
b. The ballista (ballista), which cast stones, the trough being sharply inclined, while that of the catapult was more nearly horizontal.
c. The wild ass (onager) which hurled small stones, and was an effective engine, but was not used till after Caesar's time.
The other operations of the siege varied according to circumstances. When the ground allowed, the walls were undermined and tunnels run under the town. Meanwhile, of course, the besieged were not idled. Mines they met by counter-mines. With great hooks they tried to catch the head of the battering-ram and hold it, or let down masses of wood or wickerwork along the side of the wall to deaden the force of the blow, or drew the wall-hooks over into the city with windlasses (VII. xxii. 4-6). By frequent sallies (eruptiones) they endeavored to destroy the works of the besiegers, drove the workmen from their posts, and hurled firebrands into the sheds and towers. Owing to the amount of wood used the danger from fire was great. Sometimes even the mole was burned (cf. VII. xxv. 11 et seq.) When a breach had been made in the wall, or a gate battered down, an attack was begun wherever it was thought possible to force an entrance. The mole and towers were connected with the top of the wall by means of planks and beams thrown across. Detachments of soldiers, holding their oblong shields close together above their heads, formed a tortoise-cover, under which they marched up close to the walls and tried to scale them, or entered the breach. So carefully planned were their works, so powerful their military engines, and so irresistible their onset, that the Romans rarely failed to reduce a city which they had determined to take.
X. The Roman War-Ships
The war-ships (naves longae) of Caesar's time rarely had more than a single sail, and were propelled mainly by means of oars. There were usually three rows or banks of oars (triremes); but we read of vessels with one, two, four, and even five banks of oars. The rowers kept time to the sound of a horn or click of a hammer. The rudders (gubernacula) were not like those of today, but consisted of two large paddles thrust down into the sea on both sides of the stern. The anchor was like those of our time. At the prow, near the water-line, was the ship's beak (rostra), consisting of one or more sharp metal-pointed beams thrust out some distance, the aim of which was to pierce the side of the enemy's vessel.
Before going into action the sail was rolled up and the mast taken down; a tower was raised on the front part of the ship, from which missiles could be hurled over into a vessel near at hand; grappling-hooks were provided, by which the opposing ship might be seized, and a movable bridge that could be thrown across in boarding. The ensign was a square or oblong flag (vexillum); that of the admiral's vessel was distinguished by a purple color. Ships built for quick movement, for inspecting the enemy's strongholds and harbors, and similar undertakings (naves actuariae), were small and light. For the carrying of his troops Caesar used transport-ships (onerariae naves), which were broader and slower than the galleys; these were accompanied by war-ships as escort (IV. xxii. 13 et seq.; V. viii. 13-15).
The Roman naval tactics consisted mainly in either propelling a vessel with great force against a rival and crushing the side, or in catching hold of the hostile craft with hooks, pulling alongside, springing over on it, and settling the conflict with a hand-to-hand fight. In the sea-fight with the Veneti, who had only sailing vessels, the Roman sailors crippled the enemy's ships by cutting down the sail-yards. (III. xiii-xv).