Frumentarii

Frumentarii acted as the secret service of the Roman Empire. There are two main sources of information about the frumentarii, inscriptions on gravestones and anecdotes where the actions of individual frumentarii are mentioned by historians. From what is known of the Frumentarii, they always worked in uniform. The Empire was based on patronage, not an ideology (until Theodosius I). From inscriptions; one of the few things known about the frumentarii is that they were mostly attached to individual legions, except for a few centurion frumentarii. Attachment to individual legions suggests that their main function was, as the name suggests, to service those legions with supplies.