The organization of the Empire by Augustus also entailed the creation of organizations entrusted with tasks until that time attributed confused and among these was the establishment of a military detachment that today would be called "intelligence".
It consisted of miles peregrini, or foreign soldiers who came from the provinces and had their landing in Rome because they were directly under the orders of the emperor and the Urbe departed to reach the provincial territories. On the hill of Celio, Augustus built for this special detachment an independent camp called castra perigrinorum.
Castra hosted three distinct types of milites: the frumentarii, the speculatores and the exploratores.
There are references to the frumentarii already from the second century. AC when, as the wars became increasingly and more military campaigns fought far from the borders, it became necessary to organize a department to handle supplies. These soldiers were involved in the collection of food and the escort of convoys and were also called Mensores frumentarii or Mensores tritici; they were specialized soldiers part of immunes, then it was a detachment of quartermasters whose job it was to acquire the food, hence the name of frumentarii.
The expansion of the tasks was a consequence of freedom of movement of these detachments that were composed of foreigners and staffed by non-commissioned officers and centurions involved in purchase of cereals for the legions, for this reason constantly traveling between Rome and the provinces. They were in contact not only with legion officers, but they also had contacts with suppliers, logistics officers, local officials, farmers and merchants; This network of relationships allowed them to gather information in any part of the empire. They traveled for the empire by keeping the map of the road structure up-to-date, signaling orographic and hydrographic changes, the birth or abandonment of the inhabited towns, the situation of crops and farms; this information was valuable to the Roman armies that could operate well in theaters of war, even distant.
The tasks of speculatores and exploratores were different; the first was a body of knights, in fact they were scouts but over time they became responsible for internal security, while the latter had the task of supervising the enemies although they could also be deployed in battle as cavalry. The role of both was from the beginning assimilated to the spy, occult speculator, because they did not wear the military uniform.
The barracks of the Castra Peregrina built by Augustus could accommodate about four hundred men, probably half the men of the entire operational strength as a similar number of frumentarii was deployed in the provincial capitals. The frumentarii, the main guests of castra, maintained the roles of the legion of origin, but were subjected to a different chain of command. When they were in Rome, they formed a regularly organized unit, the numerus frumentariorum, and were subjected to a centurion who made them a commander. To stand out from the other troops, this centurion had the title of Princeps peregrinorum (Commander of Foreigners) ...
by M.L. ©ALL RIGHTS RESERVED (Ed 1.0 - 19/04/2017)