helmet and greaves. The Roman attack differed from that of the Greek phalanx, in that, instead of fighting shoulder to shoulder and closing in together as gaps were made, they adopted a loose formation, which permitted the soldiers in the rear to fill up gaps caused by casualties, and thus maintained their front intact. In combat the triarii used the pilum, a short, heavy spear which they threw into the ranks of the enemy before engaging them with the sword. The three divisions of the legion (hastati, principes, and triarii) were each arranged in ten companies (manipuli), to each of which was assigned a detachment of velites. The manipulus was under the command of a centurion (centurio), whose lieutenant was a junior centurion. In the event of the disablement or absence of the officer commanding the legion, command would devolve on the senior centurion of the first company of the reserve (triarii). Normally, the chief command was taken two months at a time by each of the six military tribunes (tribuni militum). With the first civil war, however, arose the necessity of a single permanent chief, which arrangement was eventually adopted; a single officer (legatus) commanding each legion, assisted by a staff composed of the former military tribunes. The year B.C. 276 witnessed the advent of the professional or paid soldier. The long and heavy wars with Pyrrhus and Carthage led to the formation of a regular army; so that dating from the time of Marius (or from the beginning of the First Century B.C. ) the enlisted man served for a period of twenty years. The legion, as now arranged, was composed of 6000 men, divided into 10 cohorts of 600 men each, all armed with the pilum. The velites were replaced by foreign mercenaries, of whom the most famous were sagittarii (bowmen) from Crete; iaculatores (javelin men) from Mauretania; and funditores (slingers) from the Baleares. With the exception of a few Roman equites, who held the more important positions, the cavalry also was entirely foreign. Organized into cohorts were auxiliary troops of infantry and cavalry. The next reorganization took place toward the close of the First Century B.C. under Augustus, who, besides confirming the period of service as twenty years, also introduced the pensioning of veterans. Twenty-five legions were now established and distributed in different parts of the Empire. Subsequently great changes took place in the army. The typical Roman soldier was no longer the invincible legionary, who, covered by his shield, had fought his way through the most stubborn pikemen, beaten back great hordes of Eastern horsemen, and resisted the wild rushes of impetuous Celts and Germans.
At the beginning of the Third Century A.D. the work of Augustus and others was beginning to fall to pieces; in the Fourth, it was scarcely anywhere in evidence, and by the end of the Fifth it had become a thing of the past. The exigencies of border warfare, with the extended system of permanent camps connected by patrols, had developed cavalry and light infantry at the expense of the older legion. In the Third Century A.D. the elaborate system of frontier defense and interior garrisons broke down, and the Empire was subjected to both civil war and foreign invasion. While the legions were engaged in civil strife, the opportunity of the enemy arrived. The frontiers were simultaneously attacked, and the Empire reeled under the shock. The Persians were rising to power in the East (A.D. 226); the German tribes were confederating and becoming correspondingly formidable; and the Franks, Alemanni, and Goths appeared along the Rhine and the Danube. Diocletian, however, with the reconquest of Britain in A.D. 297, restored the Empire to a semblance of its former power and unity. With the aid of wholesale taxation he replenished the exchequer, and regarrisoned the military frontier. The changes and additions brought about by Diocletian are remarkable for the value he placed on the troops of mixed nationality and for the growing neglect of the ancient Roman legion. He also enlisted many new bodies of horsemen: cunei, alæ, vexillationes, etc., being raised alike for the limitary, the comitatensian, and the Palatine armies, among whom Germans, Moors, and Persians were more numerous than the born subjects of the Empire. Under Constantine, the old legionary cavalry disappeared altogether, and cavalry and infantry became separate commands; yet under him and his successors, though cavalry grew considerably in relative importance, the infantry still remained the more important arm. The decadence in physique and morale of the Roman army at this time was largely due to the fact that the corps were less homogeneous, and the substitutes and recruits bought by the land-holding classes were often of bad material. The increasing boldness of their foes and the constant civil and internal dissensions had a baleful effect on the old-time esprit-de-corps of the rank and file, and, together with the growing luxury and increasingly enervating vice of the times, soon brought about the disintegration and decay of the magnificent Empire. It is interesting to note that in many instances modern conditions have compelled the adoption of units of military command and forms of military procedure strikingly similar to those of the Romans; while the legionaries' sword, after passing through the radical forms and changes of the Middle Ages, has again appeared in the shape of the modern infantry sword-bayonet, which in shape and size closely resembles the Roman sword.
MODERN ARMIES.
The evolution of the modern army has been along the lines of national and mechanical development; national needs and aspirations dictating its origin, organization, and strength, and the progress of mechanical invention its tactics and equipment. Mediæval armies, whose organization and characteristics will be found discussed under Feudalism, were made up chiefly of the retainers, dependents, and followers of the nobility; and were usually employed in the petty struggles of their leaders, or in assisting the King to make war on a larger scale. The success of the King invariably meant gifts of land to the victorious nobles fighting under his banner; who, in turn, rewarded their knights and squires by smaller gifts of land, or land privileges, thus building up the feudal system. The holding of lands implied service due to the giver, and as a consequence many of the nobility vied with their king in power and prestige. The Crusades did much to develop the idea of