The army steadily evolved over the centuries from one constituted of rich men required to support themselves, to one which needed increased public funds. Structural reorganization of the army was ready to be made by the time of Marius: the state treasury had already started funding the army ten years earlier at the time of Gaius Gracchus, because the class qualification had dropped below the level at which the soldier could afford his own gear. Thus the equality of the soldiers' equipment had grown as a result of the treasury's uniform funding. The complete dismissal of the property requirement demanded a reorganization of the army, in which the old divisions were based on wealth and experience. With these two elements gone, and with the influx of volunteers enlisting with hopes of booty from war, legionnaires would be all but equal. This equality lent a flexibility to the army which Marius was able to utilize tactically through his creation of the cohort.
The switch of the primary legionary division from Maniples to Cohorts was the greatest change for which Marius is credited. This switch is clearly related to the fact that there was no longer a land requirement to serve in the military; accordingly, there was no difference between the type of weapons each group carried, since everyone was being supplied by the state.
In the Maniple system that existed before Marius, there were four divisions: the velites, hastati, principes and triarii. Originally there were only three, but the unarmored velites, comprised of the lowest class, were added as a solid first line offensive force of 1200 men. Velites were equipped with swords, javelins and a small circular shield (the parms). They were also recognized from a distance by the wolf skin they wore over their helmets. The second group was the hastati (whose helmets had tall upright feathers to exaggerate their height. They were followed by the principes, men who were usually equal in economic status to the hastati but in the prime of their lives. The groups had 1200 men, each carrying the oval scutum, the short Spanish sword (gladius), and two pila (one heavy and one light). Last were the triarii who were the oldest men. They were similarly armed with the addition of a thrusting spear (the hasta). There were also a small token group of equites, named for the horses they rode on. See the figure (below) to understand the battle formation.
The cohort was adapted from the existing maniple system. The maniple legion broke down into 10 maniples. Each one included seven centuries of 60 men. These seven centuries were divided as follows: 2 of velites, 2 of hastati, 2 of principes, and 1 of triarii. See figure (right).
The cohort eliminated the poorly armored velites and created three groups of two centuries each with 80 men, for a total of six centuries ( 480 men). The legion was made of ten cohorts yielding a force of 4,800 men. Eventually the century would be raised to its literal number of 100, yielding a legion of 6,000 men.
|Velites and triarii were armed with a javelin, thus making them like the core of the former maniple rather than a light screen of men or a last line of defense. Each cohort was made up of a contingent of each type of man from the former system. Thus, the cohort of 480 had the same first, second and third wave structure as the entire former legion. Due to this innovation of flexibility, the cohorts formed up for battle not as long lines but as individual cohorts, each capable of fighting entire mini-battles, with three waves of attack.|