The Frumentarii were an ancient Roman military 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. History It had been a long-standing policy of the Roman legions and armies of occupation to utilize informers and spies, but never in an organized fashion. This was especially true in the city of Rome which was rife with whispers and endless conspiracies. The frumentarii was possibly established by Domitian, although they only appear in records shortly after his reign in the early second century. When established, their base was located at the Castra Peregrina on the Caelian hill, though Trajan would later centralize their location in Rome. During their early history, they were tasked with supplying grain to the military, delivering messages between the provinces and the empire, and collecting tax money. They were sometimes called Nomads Nomas in Latin, to protect their identity in enemy territory. After the end of the Flavian Dynasty, the frumentarii developed into a police force. They worked as non-commissioned officers with praetorian cohorts to police the populace. This organization was part of the military, and its members were legionaries. Members of this group were recruited from the military. By the 2nd century, the need for an empire-wide intelligence service was clear. But even an emperor could not easily create a new bureau with the express purpose of spying on the citizens of Rome's far-flung domains. A suitable compromise was found by Hadrian. He used the frumentarii as a spying agency because their duties brought them into contact with enough locals and natives, allowing them to acquire considerable intelligence about any given territory. Alongside these duties they also may have overseen and guarded mining operations. They served as secret police and as an intelligence agency in ancient Rome. Emperors would use them to gather information on friends, family, officials, or soldiers. This organization was sometimes tasked with assassinating whomever the emperor wished. Peasants disliked the frumentarii due to false and arbitrary arrests. They were seen as a tyrannical "plague" on the empire. These complaints lead to the disbandment of the organization in 312 CE during the reign of