Frumentarii

thumb|upright|Inscription about a frumentarius from Legio VII Gemina.

The frumentarii were an ancient Roman military and secret police organization used as an intelligence agency. They began their history as a courier service and developed into an imperial spying agency. Their organization would also carry out assassinations. The frumentarii were headquartered in the Castra Peregrina and were run by the princeps peregrinorum. They were disbanded under the reign of Diocletian due to their poor reputation amongst the populace.