There is a dispute among historians over whether the Roman Empire collapsed because of its increasing size and system-imminent flaws which were not suited for this size. The bigger the territory, the harder to govern it efficiently. It is possible this factor could also be viewed in regards to today's large Russia and very large companies where the communication lag within a system increases.

This brought me to the question: How was communication in the Roman Empire set up, and did it exist in a holistic way at all? How were orders and information (feedback from marginal regions) transported or brought to important decision makers? Did the Romans use horsemen, runners, carrier pigeons, or a form of postal service? How reliable was this and on what time schedules did a person-to-person exchange happen (letter and reply letter)?

Can anyone here shed some light on this process and its limitations, or implications for a consistently increasing Roman Empire? Is it safe to assume it must have played an important role when analyzing the success and then the demise of the Roman Empire?

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    Quick and dirty (I'll likely expand in answer format later) is that yes, it was a problem. As you state it was large, very large. So large in fact that the Roman Empire (in its latter days) was split into a Western and Eastern Empire that were autonomous from one another. Autonomy included as well as their respective inter-empire communications, yes, communication was a problem in general. Oct 13, 2011 at 1:58
  • One strength of the empire was how it could blend centralized and decentralized institutions. When at least some of the affairs dealt locally, you can decrease the negative effect of these lags.
    – Greg
    Mar 19, 2019 at 0:27

6 Answers 6


Throughout history this has proven to be a difficult task for a number of empires, including the Greeks, the Chinese, the Persians, and the Romans. The larger their territory, the more difficult it became to manage and control them. The real shortcoming was in the inability to communicate quickly and effectively.

In some instances, those who needed approval or support were hesitant to act without the proper authority, and the delays in obtaining responses led to their downfall. One of the ways that some tried to handle this was to appoint leaders with the authority to make all decisions throughout different regions of the empire. Ultimately, this tended to lead to power struggles which inevitably brought about the downfall of the empire.

To address the question of how the Romans communicated, there were a number of different methods used, depending on what was available or most expedient. In some cases they would use runners, while in other cases they would use a horseman. There were also situations where they would send a military legion to escort an officer or official dignitary who was entrusted to deliver a personal message. I don't recall reading anywhere that they used carrier pigeons.

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    A legion to escort a messenger? Are you joking?
    – Anixx
    Nov 22, 2012 at 3:51
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    @Anixx in the cut throat world of roman politics, "killing the messenger" is a legitimate tactic - Hence the need for protection.
    – user1524
    Nov 23, 2012 at 8:03
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    @NWS lol, protection by a legion? Was the messenger besides delivering a message also ordered to capture the country?
    – Anixx
    Nov 23, 2012 at 8:26
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    @Anixx, sometimes it would be a show of strength, delivering a message with a whole bunch of swords behind it. Sometimes it would be a VIP delivering the message, and they needed to be protected. Sometimes the legion would be headed in the same direction so they just traveled together, and sometimes it was just the vanity of the leader who wanted a big entourage. And as for carrier pigeons, they didn't come along until much later in history.
    – Nerrolken
    Dec 13, 2013 at 18:03
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    This answer could benefit from some citations and/or examples
    – DVK
    Feb 24, 2014 at 22:20

The Roman Empire had the cursus publicus, which maintained an infrastructure of horses and way stations. The messenger himself was supplied by the one sending the message. It was used for transporting messages, magistrates, and some heavy goods too. Important messages typically travelled at roughly 50 miles per day.

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    The cursus publicus was a direct predecessor of all modern Western mail, so it feels strange to describe it as "something analogous to US pony express". en.wikipedia.org/wiki/Mail
    – kubanczyk
    Nov 22, 2012 at 13:23
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    This is nice, but how does this answer the question?
    – o0'.
    Oct 17, 2014 at 9:47

I think that the short answer to your question is: No. The Empire survived very well for about 400 years (let's say from the death of Augustus in 14 CE to circa 400 when the so-called migration of the peoples began to be felt in the Empire) with the same communications structure.

Ancient states required much less centralized decision making than modern ones and the cursus publicum system that was mentioned in another answer (there was a naval system as well, by the way), together with a considerable degree of autonomy given to governors, sufficed for the Empire's needs.

The division of the Empire had, in my opinion, more to do with political exigencies created by increasing external pressure, than with communications problems. There were more threats to respond to beginning with the Gothic invasions of the late 3rd century, but the Emperor could never trust a subordinate with too much military power, because the later was almost sure to turn upon him at some stage; the only practical solution that worked was to divide the Empire and its army. The problem here was not technological, it was political.

  • It's a political problem deriving from a technological problem: if your Rome-to-frontier communications loop is several months long, you need to give your general a certain amount of independent authority if he's going to be at all effective. And generals with independent authority tend to get ideas about what to do with that authority.
    – Mark
    Mar 19, 2019 at 23:02

From Wikipedia

"In order to maintain control and improve administration, various schemes to divide the work of the Emperor by sharing it between individuals were tried between 293 and 324, from 337 to 350, from 364 to 392, and again between 395 and 480. Although the administrative subdivisions varied, they generally involved a division of labour between East and West. Each division was a form of power-sharing, (or even job-sharing) for the ultimate imperium was not divisible and therefore the empire remained legally one state—although the co-emperors often saw each other as rivals or enemies rather than partners."

That is probably the best evidence that the cost of communication rose to be impracticable; the Emperors divided the empire because it was not possible to exercise imperium.

I think it would be interesting to (a) examine the rise of the proconsul as an adaptation of the Roman Republican system to the increased cost of communication and (b) the general question of how the Roman Republic balanced delegation of power against the difficulty of maintaining oversight (I'm going to assert that within the context of your question the value of communications is the exercise of oversight) - but those questions are far beyond the scope of stack exchange. (

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    thx, added the wiki link. The mixture of federalism <-> centralism in todays states brought me to this question
    – Hauser
    Nov 26, 2012 at 13:39

I have to agree with @Felix Goldberg. Communication wasn't the real problem. Remaining in power most certainly was, for many emperors. The mortality rate of emperors was as high as gladiators. Not that many died peacefully in bed.

Communication was done with the cursus publicus which remained more or less in tact until the very end of the empire. That system had worked well when the empire was at its largest extend, so communication cannot be the real reason for its demise and split of the empire.

What I notice is that both provinces and military units progressively become smaller over time. Part of that may well be to make better management possible. A far more important reason is to make it more difficult to revolt.

A governor controlling a large part of Gaul with 4 or more legions is far more dangerous to the emperor than a governor that governs a much smaller province, especially if the military command is separate. The governor would hold political power but not military power to make a bid for the purple, and the military commander didn't have the political power to support him. In both cases the governor(s) and the general(s) had a lot less political and military power than in the past.

Which, at least for a short time, solved another problem: more governorships and military commands to share out to adherents. In other words: the pie was sliced in thinner slices to satisfy more people. The long term problem was that once more people shared in the pie, they invariably wanted a larger piece of it.

How was communication in the Roman Empire set up

The cursus publicus was the Roman equivalent of the Pony Express. All throughout the empire were stations where riders and important travelers could change horses and riders. That way a message could reach Rome within about 10-15 days.


The effect of increasing the size of Roman Empire affected the control of the Senate over the armies. While Rome was only a small city, the Senate was able to choose Consuls for each year, and rise an army for each campaign.
But, when Rome increased its size, it was necessary to keep armies far away of the city, so the members of the army started to be professional soldiers loyal to their commander, instead of citizens loyal to the city.
Civil wars in Rome started because soldiers were loyal to their Generals. And Generals were independent enough because they were far away of the city. Most rebellions in Rome started in remote places, not near Rome or Constantinople.

The first civil war, was because the Senate was afraid of Caesar, and asked him to leave his legions and return to Rome. He returned, but with his legions with him. Those legions were loyal to its General, because they fought together for almost ten years.

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