Espionage in Ancient Rome

The Romans prided themselves on being a people who won their battles the hard way. Roman writers claimed that their army did not defeat its enemies by trickery or deceit but by superior force of arms, and for the most part they were right. The Roman legions could outstrip almost any opponent in maneuverability and discipline. By relying on sound tactics, strategic methods, and superior logistics, the Roman army made itself the most reliable killing machine in the history of pre-mechanized warfare. It has been estimated that the Romans’ standard weapon, the gladius, or Spanish short sword, accounted for more deaths than any other weapon before the invention of firearms.

What need would such a people have for spying or covert action? Were the Romans exactly as they portrayed themselves–too noble and upright to resort to subterfuge? Was it only their enemies who relied on dirty tricks and clandestine operations? Although they wanted others to believe this, the historical record shows that, on the contrary, the Romans used a full range of covert intelligence techniques, as we would expect from any power that aspired to world empire.

Discovering traces of intelligence operations that occurred two thousand years ago–which even then were meant to be secret–is no small task. But it is not an impossible one. The intelligence business is as old as civilization itself, and once the steps in the process have been identified, they can be traced in almost any civilization that left historical records.

In the days preceding modern ‘technical’ collection–whereby sound recording devices, hidden cameras, and satellites gather data–people were the only means commanders and political leaders had to collect the vital information they needed to survive the plots of their enemies. Before bugging devices, there were eavesdroppers behind curtains, and the toga and dagger might indeed have been symbols for the way the Romans carried out their domestic and foreign policy objectives.

The modern process of intelligence gathering has four elements: direction or targeting, collection of data, analysis of data, and dissemination to the users of the information. Good intelligence analysts know that not all information is ‘intelligence.’ Intelligence is restricted to crucial information about the target or enemy–his strength, location, likely intentions, and capabilities. Also, good intelligence has a time factor; it must be quickly collected, analyzed, and delivered in time for the user to act upon it. The last step is dissemination. Even if intelligence is collected and analyzed correctly, it will be of no value if the product is not conveyed to the end user in sufficient time for him to act upon it. A famous example in the Roman context was the episode in which a list of conspirators was thrust into Julius Caesar’s hand shortly before he was assassinated. Caesar’s intelligence network had done its job. Had the dictator read the message and acted upon it, he might have survived. Taking advantage of the intelligence product–the decision to act–is not a function of the intelligence apparatus. If the commander or statesman has all the information yet makes a bad decision, it is not an intelligence failure but incompetence or poor judgment on the part of the intelligence consumer.

Rome certainly did not lack enemies to target. Neighboring clans like the Aequi and Volsci, and later the Etruscans, Samnites, and Gauls, kept the Romans constantly at war during the early and middle republics. Collecting intelligence about these surrounding tribes and discerning whether they would be friendly or hostile in a given situation was probably a full-time job, and instances of such intelligence gathering appear in Livy’s stories. Around 300 b.c., for example, during the Etruscan wars, the consul Q. Fabius Maximus sent his brother disguised as an Etruscan peasant into the Ciminian forest to win over the local Umbrians to the Roman cause. The brother was both fluent in Etruscan and a master of disguise. He was sent to reconnoiter areas into which Roman agents were said never to have penetrated. The mission was a resounding success, and Rome was able to bring Umbrian tribes into an alliance.

The Romans continued to use intelligence as they conquered the peoples of the Italian Peninsula. We see them using scouts on regular assignments against the Samnites and Gauls, and because of advance intelligence they could often catch their enemies by launching surprise attacks and rout their camps.

When Rome leaped into the international arena against the Carthaginians, however, it learned a lesson about how effective advance intelligence could be in the hands of a skilled opponent such as the Carthaginian leader Hannibal. During the Second Punic War (218­201 b.c.), Hannibal placed spies in Roman camps and in Rome itself. We know this because one of those spies whom the Romans caught had his hands cut off, then was released as a warning to other spies. The Carthaginian general’s ability to disguise himself, to forge documents, to send secret communications, and to surprise the Romans became legendary. And his agents are said to have had secret hand gestures that they used as a means of recognizing one another. Hannibal used such ingenuity to lure the Romans into traps, as at Lake Trasimene, where he caught the Roman army between the lake and the surrounding mountains. This ruse cost the Romans fifteen thousand killed and an equal number taken prisoner. His famous victory at the Battle of Cannae was another trap–a victory for Hannibal that cost the Romans dearly in lost manpower. Although historians have argued over exact figures, when Livy tells us that the rings taken from dead Roman aristocrats filled three bushels, we get some idea of the loss to the Roman upper classes.

Not only did Hannibal emphasize good intelligence, he exacted a high price from agents who did not perform well. A scout who had mistakenly taken him to Casilinum and into a trap, when he had been directed to take him to Casinum, was crucified as punishment for his error.

Hannibal had the advantage of being sole commander of his forces. As leader of the Carthaginian army and its allies, he was his own chief of intelligence for fourteen years. It was not until the Romans put a single commander, Scipio Africanus, in charge of their armies that they were able to emulate Hannibal’s efficient tactics and win the Second Punic War.

Among other ploys, Scipio directed spies to reconnoiter enemy camps. When his siege of Utica stalled, he sent a legation to the camp of the Numidian king, Syphax. Centurians disguised as slaves accompanied Scipio’s emissaries. The legate Gaius Laelius was fearful the plan would be exposed–that one of the disguised centurians, Lucius Statorius, might be recognized since he had previously visited the camp. To protect his agent’s cover, Laelius had him publicly caned. The persuasiveness of the deceptive action hinged upon the known fact that the Romans subjected only persons low on the social scale to corporal punishment. To the historian, the episode is of particular interest because it specifically identifies centurions and tribunes as active participants in espionage missions. While the legates were in conference, the’slaves’ were to wander about the camp and reconnoiter the premises, making note of entrances, exits, and the location of each division. They were to look for the outposts and sentries and determine whether the camp was more vulnerable to attack by day or by night. On each visit, a different group of’slaves’ made the trip, so that every centurion would have an opportunity to familiarize himself with the encampments.

When all the information was at hand, Scipio concluded that a night attack would be the most effective way to take the camp, and in addition, he ordered the Carthaginian and Numidian camps burned. The Carthaginians, thinking these were accidental fires, ran out unarmed only to be slaughtered by the Roman column that was ready and waiting. In this case, intelligence collection had made possible a successful clandestine operation. Scipio had delivered a crippling blow to a superior force.

By the time Rome conquered the Hellenistic kingdoms in the East and fought the Third Punic War (149-146 b.c.), the republic on the Tiber had become the center of a Mediterranean empire. Historians still marvel at how much territory Rome ruled during the middle republic with the sparse infrastructure that it had. For example, there was no postal-communications system, no government intelligence service, no permanent foreign service, and no decision-making body other than the cumbersome three-hundred-man Senate. The Romans had nothing resembling a diplomatic corps. They did not send permanent representatives abroad, nor did they establish offices for foreign-area specialists at home. In fact, they did not even install occupying forces in the East prior to the late second century b.c. There was no diplomatic presence abroad to implement foreign policy, to provide cover for covert operators, or to act as intelligence gatherers for the government back in Rome.

The primary means of assessing problems overseas became the embassy. The Senate dispatched small missions of inquiry or advice, composed usually of three to five senators of varying qualifications and experience. They traveled in naval vessels but without military escort. These men acted as Roman agents but were by no means permanently stationed abroad. Embassies were usually sent to visit kings who had previously sent deputations to Rome to ask for assistance. Only in times of crisis would the Senate initiate a mission of inquiry on its own.

Roman envoys were briefed with instructions and told to deliver warnings, to give advice, to arbitrate settlements, to check reports, or simply to look around. Most of this was done in the open, but there was always the possibility of information being clandestinely slipped to the envoys by interested parties. We do not know how many retainers they brought with them who, unnoticed, could eavesdrop.

While it is reasonable to assume the Romans sent the emissaries to collect intelligence, there is no question that the emissaries were considered spies by their targets. On his grand tour of the East in 166 b.c., Tiberius Gracchus and his entourage were referred to as kataskopoi (spies) by the Greek historian Polybius. Appian, another Greek historian, bluntly stated that envoys sent to Antiochus IV, ostensibly to bring about reconciliation between him and Ptolemy, really intended to find out his plans. Antiochus gave these spies such a warm reception that they sent back glowing reports. Yet we know from other records that Antiochus in fact harbored a great deal of antipathy toward Rome and pursued a policy quite different from the one he confided to the envoys.

Because rulers in the East had a long history of using formal intelligence services, they often assumed the Romans were playing the same game. Genthius, an Illyrian king, sometimes chained ambassadors sent by Rome and charged them with espionage. Other examples of Roman ambassadors or traders being suspected, arrested, or executed on espionage charges are not hard to find. Even Romans traveling in a non-official capacity were mistrusted by provincials. Roman grain buyers making purchases from Cumae and Sicily were accused of spying, and consequently were treated with extreme hostility by the local authorities, even to the point of finding their lives in danger. When Mithridates VI, king of Pontus, went to war against the Romans, the first thing he did was kill all the Romans and Italians in the main cities of Asia Minor as members of a possible fifth column. An estimated eighty thousand Roman and Italian casualties show how seriously Mithridates took his security problems.

Part of Rome’s reluctance to develop a formal intelligence service stemmed from the unique way its republican government had developed. The Senate, composed of scions of wealthy, upper-class families, acted with a certain amount of class loyalty that allowed the state to push its interests and expand overseas. But the senate was not of one mind. There was always tremendous personal competition among individuals and families for the wealth and glory that such conquest created. In order to further their parochial ends, these men needed to know what others were doing and planning, and so they used their private intelligence networks to advance their own careers. Much of the behind the scenes cloak-and-dagger work of senatorial politics is forever lost to us, but it is not hard to imagine what forms it took. Certainly political scandal played its part in launching as well as sinking the careers of numerous senators.

The Romans had no qualms about using espionage on a personal level. Every Roman aristocrat had his private network of business associates, informers, clansmen, slaves, or agents (male or female) who could keep him informed on the latest happenings in the Senate or his own home. Even Roman architects built private homes with counterintelligence in mind. Livius Drusus’ architect asked him whether he would like his house built ‘in such a way that he would be free from public gaze, safe from all espionage and that no one could look down on it.’

Espionage on a small scale became espionage on a national scale when the nobility took its family interests into the foreign-policy arena. But because each senatorial family had its own private intelligence network, no one group would have sanctioned the creation of a single central intelligence organization that might fall into the hands of a rival faction. Such a collection of individual interests was simply not fertile ground for spawning a single institution that would monitor Rome’s overseas interests plus segments of Roman society itself. Even if such a centralized intelligence body were assigned only foreign targets, there might have remained a residual fear that sooner or later such an apparatus would be used to advance the interests of one group over another.

The fact that the intelligence networks were privately owned and operated can be seen clearly in the late republic. Sallust, who wrote an account of the Catiline conspiracy, one of the most notorious threats to the late republic, said it was put down by Cicero using bodyguards, who learned of it through the consul’s wide-ranging espionage network that included bodyguards. Pompey and Caesar each had intelligence networks that they used against each other in the civil war that ultimately brought down the republic.

Caesar’s agents in Rome kept a close watch on his enemies. Cicero, for example, mentions in a letter that his epigrams were reported to Caesar, who could distinguish between the authentic ones and those falsely attributed to him. As long as Caesar held control of Rome during the civil war, the city’s population rejoiced with his victories and mourned his losses, at least publicly. They knew full well there were spies and eavesdroppers prowling about, observing all that was said and done. Caesar’s military couriers, the speculatores, were kept busy delivering intelligence but were also given espionage assignments.

Caesar coordinated his intelligence assets well. In this he stands out as an individual who could make the best of the republican system. He established a rapid message and information transport system via couriers, and he also had scouts and spies who used counterintelligence techniques, such as codes and ciphers, to prevent his military plans from falling into the hands of the enemy. His successor Augustus had a better opportunity to develop the system Caesar had started. Augustus may have been heir to Caesar’s ideas, or perhaps he just instinctively knew what the new empire needed. But in any case, he was shrewd enough to realize that such intelligence reforms were long overdue. Augustus’ first intelligence-gathering and dissemination-related innovation was the establishment of a state postal and messenger service called the cursus publicus, which replaced the inadequate republican system of private messengers.

By furnishing a means of transport and communications, Augustus built the rudiments of what was to become the imperial security service. Now there would be an official, permanent, and reliable way to communicate political and military intelligence. Like the Babylonians and Persians before them, the Romans combined their road network with a centrally administered communications system to help ensure the security of the emperor and the stability of the empire.

Although the cursus publicus provided a reliable means of transmitting important intelligence, sending dispatches by this method did not ensure sufficient security if there was a traitor within the system. Secret and not-so-secret communications often played a critical role in political events.

The emperor Caracalla (a.d. 211-217) was warned of a plot against his life as the scheme was being hatched by his successor Macrinus (217-218). The warning came from Materianus, the officer in charge of the urban cohorts during Caracalla’s frequent absences from Rome on campaign. The message was sealed and given with other letters to the courier of the imperial post. The courier completed his journey at normal speed, not realizing what he was carrying. Caracalla received the mail, but instead of reading it himself, turned the daily dispatches, including the warning from Materianus, over to Macrinus, who promptly disposed of the incriminating letter. Because he was afraid Materianus might try a second communication, Macrinus also decided to dispose of Caracalla.

Quite frequently intelligence couriers doubled as political assassins. The emperor Gordian sent a secret letter that is described by the historian Herodian as having been folded in a manner that was ‘the normal method used by the emperor to send private, secret messages.’ No further details are given, but evidently such messages were sealed in a certain way and carried by special messengers. In Gordian’s case, the message was sent to the governor of Mauretania Caesariensis as part of a covert operation. The agents were disguised as messengers from Maximinus, the emperor’s enemy. The governor, Vitalianus, usually went to a small room, off the public court, where he could scrutinize the dispatches carefully. The agents then were instructed to inform him that they were bringing secret instructions from Maximinus and to request a private audience in order to pass these secret instructions on personally. While Vitalianus was examining the seals, they killed him with swords hidden under their cloaks.

As the system of the cursus publicus developed, the couriers were drawn increasingly from the army, especially from the speculatores. The duties of the speculatores were not limited simply to carrying messages. They could also be used for undercover activities such as spying, arresting political figures, guarding suspects and detainees, or executing condemned men. The Gospel of St. Mark 6:27 indicates that it was a speculator who was sent to the prison with an execution order for John the Baptist.

With the reign of Domitian (a.d. 81-96), or possibly Hadrian (117-138), came another innovation that added more manpower to this intelligence network. The supply section of the imperial general staff provided personnel who could work as intelligence agents. Supply sergeants, called frumentarii, whose original functions had included the purchase and distribution of grain, were now turned into intelligence officers. Because these men were constantly traveling on logistical assignments, they were in a position to watch over the army, the imperial bureaucracy, and the local population. They could report back on any situation that was of interest to the emperors. That emperors came to rely on this system is shown by the fact that the frumentarii began to replace the speculatores as intelligence couriers and eventually as secret police. Although their three main duties were as couriers, tax collectors, and policemen, like the speculatores before them these officers were used in many capacities involving state security. By the third century there is extensive evidence of their use as spies. No one seemed to be immune–prominent generals, lowly Christians, senators, and subversives all came under their scrutiny.

In the city of Rome the frumentarii worked closely with the urban police force. Their secret service duties, besides investigating and arresting, eventually came to include political assassination. Not only did the emperor avail himself of their services, but pretenders to the throne, such as Macrinus, used the frumentarii to further their careers. How the service was used or abused depended on the emperor. Alexander Severus is praised for choosing only honest men, but at other times complaints arrived about their corruption.

Secret police agents, the frumentarii participated in the persecution of Christians. They were among the chief agents who spied on Christians and had them arrested. The soldier who supervised Saint Paul in Rome while he was awaiting trial was a frumentarius. Early Church historian Eusebius reports the tale of a Christian named Dionysius who was being hunted by the secret police. He hid in his house for four days. Meanwhile the frumentarius was searching high and low but never thought to search the man’s house. Dionysius made his escape with the help of the Christian underground.

In another incident, a frumentarius was sent to arrest Cyprian, later sainted, but the Christians, who had their own intelligence network during the persecutions, found out about the arrest order and warned him to go into hiding.

Many ancient sources mention’soldiers without uniforms’ arresting Christians or performing other secret service duties, but it is not always possible to know if these were frumentarii. Since any soldier could be seconded for police duties, the imperial government had a large range of personnel from which to choose for these kinds of duties.

Their activities did not endear the frumentarii to the general public. Roman administrators could be arbitrary, authoritarian, and corrupt. When they became involved in tax collecting and detecting subversion, the temptations to corruption were even greater. A third-century writer described the provinces as ‘enslaved by fear,’ since spies were everywhere. Many Romans and people in the provinces found it impossible to think or speak freely for fear of being spied upon. The snooping of the frumentarii became rampant by the late third century, and their behavior was compared to that of a plundering army. They would enter villages ostensibly in pursuit of political criminals, search homes, and then demand bribes from the locals.

The emperor Diocletian disbanded the frumentarii because of the massive number of complaints he received from his subjects, but he actually had no intention of giving up such an essential intelligence source. He simply replaced them with members of another organization, who would perform the same counterintelligence and security tasks but under a different name. These new men were called agentes in rebus–general agents. The blandness of the title belies their actual secret functions. They performed a wide range of intelligence activities almost identical to those of the frumentarii. The two major differences were that the agentes were civilians, not soldiers, and they were not under the jurisdiction of the praetorian prefect, the commander of the Praetorian Guard; rather they were directed by an official called the ‘master of offices.’ Since the master of offices controlled other groups that had intelligence functions–such as the notarii, the imperial secretaries–by the mid-fourth century the master of offices became, in effect, the minister of information. The new corps of agents was also more numerous than it had been under the previous system, reaching as many as twelve hundred men.

The growth of bureaucracy in the late empire created another use for spies: surveillance of other ministries of state. The central government would send intelligence officers from the imperial court to other departments of the bureaucracy to spy on both their superiors and subordinates alike. Instead of remaining loyal to the emperor, they cooperated with, rather than spied on, the superiors they thought could help their careers. Often charges of treason were hurled at political rivals rather than real traitors, with the consequence that the security of the empire was compromised.

During the late empire, the Roman government institutionalized its information services and espionage activities to an extent unknown during Augustus’ time. And yet can we say intelligence activities kept the emperor any safer? Probably not. Only a minority of emperors died a natural death. Seventy-five percent of them fell to assassins or pretenders to the throne. In order to be safe, the emperor relied on many groups to provide him with intelligence. The distinguishing characteristic of espionage in the late empire is that no one department carried it out alone. Many groups, civilian and military, were assigned tasks that involved some surveillance.

Did all this spying make Rome more secure on its borders or make its leaders well informed about its enemies? Again the answer is no. Foreign intelligence continued to be collected by the traditional means, that is, by the military scouts–the exploratores and speculatores. Large mobile units of exploratores were stationed in border areas, where they were used to monitor enemy activity beyond the empire’s limits. This was straightforward military reconnaissance. There is little evidence to suggest that the Romans placed their own agents among foreign powers. The one exception is a passage from the fourth-century Roman historian Ammianus Marcellinus in which he talks about a group called the Arcani who evidently were paid by the Romans to’snoop among the savages’ and report what they saw. Even they eventually became corrupt and had to be removed. Unfortunately for us, the detailed description of these activities was lost with Ammianus’ history of Constans, which has not survived.

Despite their protestations to the contrary, the Romans were heavily involved in espionage, but it cannot be said that they ever established a formal intelligence service. The closest they came was in using groups like the frumentarii and the agentes in rebus for various internal security tasks. Protecting the emperor and keeping him on the throne became so crucial after the third century that most of Rome’s intelligence activities were focused inward. Ironically, for all their reputation as empire builders, the Romans were never as good at watching their enemies as they were at watching each other.

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8 Responses

  1. Denise

    This article was written by Col. Rose Mary Sheldon of the Virginia Military Institute and was published in the Military History Quarterly, Autumn 2000, pp. 28-33.

  2. Kim

    I really like this article! I didn’t know that Espionage had to do somewhat with the fall of the Roman Empire. Its actually interesting because they were basically the ones who started it and its one reason that brought them down. It is definitely a well written article. I learned alot.


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