PreiTlise

There is much divergence among scholars on the actual dynamics of evolution, although no one doubts its motivating factors. For they all agree that this is the grandiose process that lies at the root of the diversity of the animal species, the result of continuous though imperceptible changes of respective organisms in the course of time. A process that may even be considered as a collective survival instinct of the species to escape the otherwise inevitable extinction determined by changing environmental conditions. The conclusion is obvious: the perpetuation oflife on this planet rests on the indispensable presupposition of its continuous adaptation to the existing context. A conclusion that also applies to human institutions, on condition that they are sufficiently lasting to encompass numerous generations, thus assuming the characteristics of an actual biological species. And the longer the period of survival the more applicable is the analogy: a phenomenon perfectly suited to a study of the Roman Am1y that, in surviving for more than a millennium, undenvent an extensive evolutionary process.

It is however indispensable, in order to analyse and define its most salient characteristics, to divide this process into periods and, most important, to review the contexts and the reasons for its various mutations. A procedure that will lead to separate sections of this account, with the principal section coinciding, just as formal maturity coincides with the most lasting existential phase of the species, with the formation of the High Empi re, a vast archaeological period that extends from Augustus to Diocletian, after which conventionally begins the Late Empire, the catabolic phase not only of the military institution but of the entire Roman organisation, culminating in its tragic demise.

These different phases of course do not present an equal abundance of sources, nor do they have similar historical relevance. And a lthough it is doubtless interesting to discuss the characteristics of the army of Monarchical and Republican Rome , modest in size and strength, it must be stated that for the former we have only narrations of little reliability, indeed often improbable legends. While the latter, which is sufficiently well documented, it was so strongly conditioned by the numerous transformations of the State and its expansionistic and aggressive policy, that its tactical po stures turned out to be so ephemeral and changeable as to make the description of this army highly fragmentary. It is a wholly different matter for the history of the High Empire, when Rome's great territorial expansion came to an end and the mission of its armed force was very simply its defence. At this point the vastness of the State and the availabi l ity of human and economic resources required infrastructural and organisational needs of extraordinary complexity that only the military could fulfil and resolve for any extended period, continuously devising the most appropriate defensive methods.

It was perhaps this singular need that led both to the transformation of a military structure of strong Italic connotations into a multiethnic army capable of operating and combating in any geographical context, from the torrid African deserts to the icy European forests, and to the development of a body of specialists with the skill to build roads, aqueducts, canals, ports and hospitals, to mention just a few of its systematic achievements. Works that turned the legionnaires not only into engineers but also, and without any recriminations, into manual workers and labourers. From the many workshops of their large bases came bricks and tiles, lead pipes and shut off valves, surgical instruments and launching weapons. And, a detail even more futuristic for the era, these items were mass produced in the thousands, standardised and economical. Their ability to dress and suitably equip an army of almost 500,000 men in uniform will not be seen again until the industrial revolution and the Napoleonic divisions. And when that time did come, it was the same system that was implemented. The result of a coalition of force and ingeniousness!