Cursus publicus

The cursus publicus (Latin: "the public way"; Ancient Greek: δημόσιος δρόμος, dēmósios drómos) was the state-run courier and transportation service of the Roman Empire, later inherited by the Byzantine Empire. The Emperor Augustus created it to transport messages, officials, and tax revenues between the provinces and Italy. The service was still fully functioning in the first half of the sixth century in the Byzantine Empire, when the historian Procopius accuses Emperor Justinian of dismantling most of its sections, except for the route leading to the Persian border. The extent of the cursus publicus is shown in the Tabula Peutingeriana, a map of the Roman road network dating from around AD 400.^[1]

Structure of the service

A series of forts and stations were spread out along the major road systems connecting the regions of the Roman world. These relay points (stationes) provided horses to dispatch riders, usually soldiers, and vehicles for magistrates or officers of the court. The vehicles were called clabulae, but little is known of them. A diploma or certificate issued by the emperor himself was necessary to use the services supplied by the cursus publicus. Abuses of the system existed, for governors and minor appointees used the diplomata to give themselves and their families free transport. Forgeries and stolen diplomata were also used. Pliny and Trajan write about the necessity of those who wish to send things via the imperial post to keep up-to-date licenses.^[2]

Another term, perhaps more accurate if less common, for the cursus publicus is the cursus vehicularis, particularly in the period before the reforms of Diocletian. We know of at least one 'Praefectus Vehiculorum', Lucius Volusius Maecianus who held the office during the reign of Antoninus Pius. Presumably he had some sort of supervisory responsibility to ensure the effective operation of the network of stations throughout the Empire and to discourage abuse of the facility by those not entitled to use it. There is evidence that inspectors oversaw the functioning of the system in the provinces and it may be conjectured that they reported to the 'Praefectus' in Rome. However, the office does not seem to have been considered a full-time job because Maecianus was also the law tutor of the young Marcus Aurelius which seems to have been his main function.^[3]

Despite this evidence that the government did supervise the functioning of the network of stations - and, presumably, its development over the centuries, the service was not supplied by a department of state in the same way as (say) the modern Royal Mail in the UK. As Altay Coskun notes in a review of Anne Kolb’s work done in German,^[4] the system “simply provided an infrastructure for magistrates and messengers who traveled through the empire. It consisted of thousands of stations placed along the main roads; these had to supply fresh horses, mules, donkeys, and oxen, as well as carts, food, fodder, and accommodation.” Thus, there was no “department of postal service” with employees paid by the emperor. The one sending a missive would have to supply the courier, and the stations had to be supplied out of the resources of the local areas through which the roads passed. As seen in several rescripts and in the correspondence of Trajan and Pliny, the emperor will sometimes pay for the cost of sending an ambassador to Rome along the cursus publicus, particularly in cases where the cause is just.

Following the reforms of Diocletian and Constantine I, the service was divided in two sections: the fast (Latin: cursus velox, Greek: ὀξὺς δρόμος) and the regular (Latin: cursus clabularis, Greek: πλατὺς δρόμος). The "fast road" provided horses (divided into veredi, "saddle-horses", and parhippi, "pack-horses") and mules, while the latter only oxen. The existence of the 'cursus clabularis' service shows that it was used to move heavy goods as well as to facilitate the travel of high officials and the carriage of government messages.

Persian influence

The Romans adapted their state post from the Persians. As Herodotus reports, the Persians had a remarkably efficient means of transmitting messages important to the functioning of the kingdom, namely the Royal Road. Riders would be stationed at certain intervals along the road, and the letters would be handed from one courier to another as they made a journey of a day’s length, which allowed messages to travel with good speed. Augustus at first followed the Persian method of having mail handed from one courier to the next, but he soon switched to a system whereby one man made the entire journey with the parcel. Although it is possible that a courier service existed for a time under the Roman republic, the clearest reference by Suetonius suggests that Augustus created the system:

To enable what was going on in each of the provinces to be reported and known more speedily and promptly, he at first stationed young men at short intervals along the military roads, and afterwards post-chaises. The latter has seemed the more convenient arrangement, since the same men who bring the dispatches from any place can, if occasion demands, be questioned as well.

Tacitus says that couriers from Judea and Syria brought news to Vitellius that the legions of the East had sworn allegiance to him, and this also shows that the relay system was displaced by a system in which the original messenger made the entire journey. Augustus modified the Persian system, as Suetonius notes, because a courier who travels the whole distance could be interrogated by the emperor upon arrival, in order to receive additional information orally. This may have had the additional advantage of adding security to the post, as one man had the responsibility to answer for the successful delivery of the message. This does not come without a cost, because the Romans could not relay a message as quickly as they could if it passed from one rider to the next.

Area of operation

The cursus operated in Italy and the more advanced provinces. There was only one in Egypt and one in Asia Minor, as Pliny's letters to Trajan attest. It was common for a village to exist every 12 miles (19 km) or so, and there a courier might rest at large, privately owned mansiones. Operated by a manceps, or a business man, the mansiones provided food and lodging, and care and a blacksmith for the horses. The cursus also used communities located along the imperial highways. These towns very often provided food and horses to messengers of the Legions, theoretically receiving reimbursement, and were responsible for the care of their section of the Roman roads. Disputes arose naturally, and for a time the central administration participated more directly.^[5]

Financial costs and the fate of the service

Costs for the cursus publicus were always high, and its maintenance could not always be guaranteed. Around the time of Nerva, in the late first century, the general cost was transferred to the Fiscus (treasury). Further centralization came during the reign of Hadrian, who created an actual administration under a prefect, who bore the title praefectus vehiculorum. Provinces were always in touch with Rome and one another. The Imperial Post gave the legions the capacity to summon reinforcements and provide status reports before any situation deteriorated too badly. The average citizen sent letters and messages to friends across the sea through slaves and travelling associates. Most news reached its destination eventually. Julian the Apostate restricted the granting of passes to the Praetorian Prefect.^[6] Notwithstanding its enormous costs, in the Eastern Roman Empire the service was still fully functioning in the first half of the sixth century, when the historian Procopius charges Emperor Justinian with the dismantlement of most of its sections, with the exception of the route leading to the Persian border (Secret History 30.1–11). The dromos continued to exist throughout the Byzantine period, supervised for much of it by the logothetēs tou dromou, although this post is not attested before the mid-eighth century and a revival of the service may then have occurred after a substantial gap. Too, it was by then a much reduced service, restricted essentially to the remains of the old oxys dromos. In the west, it survived under the Ostrogoths in Italy, as Cassiodorus reports Theodoric the Great's correspondence.^[7]

Speed of the Post

Procopius provides one of the few direct descriptions of the Roman post that allows us to estimate the average rate of travel overland. In the sixth century, but describing an earlier time, he writes:

If we knew the distance between stages, we would know how much distance there is between five stages or eight stages, and we would know the average rate at which correspondence moved along the cursus publicus. This is calculated by A. M. Ramsey^[9] in the following way: "It appears from the Jerusalem Itinerary that the mansiones, or night quarters on the roads, were about twenty-five [Roman] miles [23 mi or 37 km] apart, and, as Friedlander points out, the distance between Bethlehem and Alexandria (about 400 Roman miles [368 mi or 592 km]) was reckoned to be sixteen mansiones, that between Edessa and Jerusalem (by Antioch nearly 625 [Roman] miles [574 mi or 924 km]) twenty-five mansiones. Although no Itinerary gives a complete list of mutationes and mansiones for any road, the general rule seems to have been two mutationes between each two mansiones. This would make the 'stage' about eight and a third Roman miles [7.7 mi or 12.4 km]." Therefore the typical trip was made at the rate of 41 to 64 miles (66–103 km) per day.

There are several cases in which urgent news or eager officials traveled at a faster rate. There is the journey of Tiberius mentioned by Valerius Maximus, the news of the mutiny of Galba as recorded by Tacitus, and the news of the death of Nero as described by Plutarch.^[10] In the last two cases, it is worth keeping in mind that bad news traveled faster than good news, and quite explicitly: a laurel was attached to the correspondence with news of victory, but a feather, as indicating haste, was fixed to the spear of a messenger carrying bad news. In all three cases, as A. M. Ramsey points out, the journey is especially urgent, and the time of travel may be recorded because of its exceptional rapidness. Such cases could not be used to find an average speed of the Roman post for carrying the vast majority of items.

Ramsey, following Wilcken, illustrates the speed of the Roman post over land with examples of the amount of time it would take a message to travel from Rome to Egypt about the accession of a new emperor (in a season other than summer, when the message would travel by sea from Rome to Alexandria). In the case of Pertinax, news of the accession, which took place on January 1, AD 193, took over sixty-three days to reach Egypt, being announced on March 6 in Alexandria. Since the route that would be taken over land consisted of about 3,177 kilometres (1,974 mi)—1,400 kilometres (870 mi) from Rome to Byzantium, including the sea crossing and almost 1,800 kilometres (1,100 mi) from Byzantium to Alexandria)—and since it took about sixty-three days or a little more for the message to arrive in Alexandria, this confirms an average rate of about 32 miles (51 km) per day for this journey Roman post.

Another example, based on a Latin inscription, is cited by Ramsey. Gaius Caesar died on February 21, AD 4, in Limyra, which is on the coast of Lycia. The news about his death is found on an inscription dated April 2 at Pisa. The amount of time that the message took to arrive at Pisa is not less than thirty-six days. Since a voyage by sea would be too dangerous at this time of year, the message would be sent over land, a distance of about 1,345 miles (2,165 km). This again confirms the calculation of an average rate of about fifty miles per day.

In his article “New Evidence for the Speed of the Roman Imperial Post,” Elliot^[11] agrees with A. M. Ramsey that the typical speed was about 50 miles (80 km) per day and illustrates this with another instance, the time that it took news of the proclamation of the emperor Septimius Severus to reach Rome from Carnuntum.

These estimates are for journeys that took place over land, making use of the cursus publicus (or, cursus vehicularis). Lionel Cassons, in his book on ancient sea travel, gives statistics for the amount of time that sixteen voyages took between various ports in the Roman Empire. These voyages, which were made by and recorded by the Romans, are recorded specifically as taking place under favorable wind conditions. Under such conditions, when the average is computed, a vessel could travel by sail at a speed of about 5 knots (9.3 km/h; 5.8 mph) or 120 miles (190 km) per day. Cassons provides another table of ten voyages made under unfavorable conditions. With these voyages, the average speed is about 2 knots (3.7 km/h; 2.3 mph) or 50 miles (80 km) per day.

See also

• Agentes in rebus
• Barid (caliphate)
• Pony Express

References