The mechanism of Roman line relief

[Jim Webster]

I cannot see line relief being organised by mutual agreement between a couple of guys at the back of the Hastati and a couple of mates in the front ranks of the Principes.

My guess is that a centurion has to send a messenger saying "We need relief" and someone, probably the person he sends the messenger to, has to give the order.

Jim

[Erpingham]

We are up against a great unknown of how exactly did command and control in the Roman army work.  The army is organised in lines but those lines have no clearly defined commander.  If patrick is correct and the legion is the basic command unit, the lowest level that makes sense is that a legion judges when it is pressed and signals a change by whole line.  How a legion would judge is a bit of a mystery, however.  Or the decision could be made at wing level or army level.  Some of the later examples dug up above suggest that a wing of an army might be pressed and the third line is deployed while in other parts of battle are going better and reserves aren't needed.  In such examples, the army commander seems to make a decision.

[Jim Webster]

I wonder if it is one of the jobs given to a senior tribune. Basically he has to keep in touch with the centurions in the front line, and they'll get word to him when they need pulling out. He then either gives the order of his own authority or passes it up to the Legionary commander.
Depending on what is happening, the Legionary commander might be behind the front line anyway, but he could also have other things to worry about so it would make sense for him to have a deputy in this matter

Jim

[Justin Swanton]

If I might beat the dying horse of ordo and manipulus one more time...

Earum primam quamque primum pilum vocabant; tribus ex vexillis constabat; vexillum centum octoginta sex homines erant; primum vexillum triarios ducebat, veteranum militem spectatae virtutis, secundum rorarios, minus roboris aetate factisque, tertium [p. 460] accensos, minimae fiduciae manum; eo et in postremam aciem reiciebantur.

I mistranslated this. tribus means 'three' in the ablative plural, hence:

The first of these parts was also called the primus pilus. It [the company] consisted of three banners. 186 men were a banner [perhaps: the banners were 186 men in total]. The first banner led the Triarii, a force of older men of known ability, the second the Rorarii, of lesser strength in age and deed, the third the Accensi, the least capable, who were relegated to the last line.

That these maniples must be hastati becomes clear when we do the sums for legion strength as a whole.  The rear-line 'ordines' provide 15x180 (or 186) = 2,700 (or 2,790) legionaries out of 5,000-ish.  This leaves 2,300-ish to come form the first 30 maniples, half of whom are principes.  Dividing 2,300 by 30 gives 76.67 men per maniple, suggesting 80 men per maniple (as opposed to 60 per vexillum in the 180-strong ordo).  We can thus see that a maniple (of 80 men) is not interchangeable with a ordo (of 60 men), and it may be instructive that Livy never refers to an 'ordo' of hastati or principes in this description (they are always 'manipuli') but always uses 'ordo' to denote the pilani, the assemblage of triarii, rorarii and accensi under the standards.

Two points: first, Livy's ordines are flexible in size. He starts by defining an ordo as 63 men in strength, then a few lines later he gives it a strength of 186 men when referring to the ordines behind the Principes.

Second, he describes the fighting style of an entire army made up of 'these companies' [ordines]:

Ubi his ordinibus exercitus instructus esset, hastati omnium primi pugnam inibant. si hastati profligare hostem non possent, pede presso eos retro cedentes in intervalla ordinum principes recipiebant. Tum principum pugna erat, hastati sequebantur. Where the army was formed up in these companies, the Hastati were the first to engage in battle. If the Hastati could not prevail against the enemy, they were received, as they fell back under pressure, into the gaps of the Principes' companies. The Hastati followed the Principes as they took up the fight.

Here, his ordinibus refers not only to the Triarii-Rorarii-Accensi combination, but also to the Principes and Hastati. Ordo is a loose, generic term, denoting any ordered body of infantry of whatever size or composition.

[Patrick Waterson]

If we turn the page to Livy VIII.10.1-2, we get:

"... the consul Manlius learned of his colleague's end, and having paid to so memorable a death —as justice and piety demanded —its well —merited [2] meed of tears as well as praise, he was for a little while in doubt whether the moment were yet come for the triarii to rise; but afterwards deeming it better to keep them fresh for the final push, he commanded the accensi to advance from the rear before the standards."

Here the consul is deciding which line will be committed and when: I suspect this was standard practice and the whole army thus changed lines at the same time.  One advantage of an infantry battlefield about 800 yards wide is that one man could keep an eye on the entire battle and judge accordingly.  In the Livian legion he (or the nearest tribune) could send in rorarii to patch a local difficulty, the line changes being kept for when local repair was past helping.  In the Polybian legion the consul definitely commanded when and how line relief and, in some cases, whole legion reserve commitment, should take place (see, for example, Polybius XV.14, where Scipio decides what each line will do, and Livy XXX.18.1-4, where the proconsul clearly commands but allows a praetor to use his own initiative).  This was an army-level command decision, and I can think of no instances when individual legions made their own choices.

[Patrick Waterson]

If I might beat the dying horse of ordo and manipulus one more time...

If it can be done without cruelty ... 

Two points: first, Livy's ordines are flexible in size. He starts by defining an ordo as 63 men in strength, then a few lines later he gives it a strength of 186 men when referring to the ordines behind the Principes.

The 63-man 'ordo' looks just like a 60-man vexillum with two officers and a signifer.

I suspect the survival of a sentence that should have been eliminated from the finished draft (when Livy finally got his own terminology straight) but never was.  It looks clumsy even in the Latin, and I observe that some translators opt to leave it out entirely.

Second, he describes the fighting style of an entire army made up of 'these companies' [ordines]:

Ubi his ordinibus exercitus instructus esset, hastati omnium primi pugnam inibant. si hastati profligare hostem non possent, pede presso eos retro cedentes in intervalla ordinum principes recipiebant. Tum principum pugna erat, hastati sequebantur. Where the army was formed up in these companies, the Hastati were the first to engage in battle. If the Hastati could not prevail against the enemy, they were received, as they fell back under pressure, into the gaps of the Principes' companies. The Hastati followed the Principes as they took up the fight.

Here, his ordinibus refers not only to the Triarii-Rorarii-Accensi combination, but also to the Principes and Hastati. Ordo is a loose, generic term, denoting any ordered body of infantry of whatever size or composition.

Fair enough.  I would however be careful to distinguish between the general use as 'formation' (and apparently subordinate formation) and the specific use as 'assemblage of three vexilla of pilani which are grouped together but which appear to act separately'.

One might postulate that each maniple of hastati was grouped with a maniple of principes in an 'ordo' of its own, but without specific mention this is of course conjectural - and does nothing to clarify 'in intervalla ordinum'.

[andrew881runner]

explain me: so if there were no gaps between manipula, where was the famous flexibility or Roman legion? which was the difference between a legion and a phalanx on more lines? we know that Romans at the beginning used a real phalanx on 5 lines based on wealth. This is the age of King Servius who changed the army.
Now, we know that the Romans abandoned the phalanx, the round Shields to use different weapons and armors and a more flexible system.
Now, was this system really different if it was simply 5 ranks where people were put depending on wealth and age, so equipment?
I think that intervals between manipula would allow not only the relief system we talked about, but even a faster and easier movement on battlefield of the deployed legion, which could manoeuvre in every battlefield, because manipula could avoid natural or artificial obstacles simply going around them. Something a normal phalanx deployed with  no gaps cannot do. And thus is why legion was superior to phalanx, because it could move and deploy everywhere, not only in open flat fields. This is what Romans learned from samnite wars throughout the Latin wars and slowly developed to the so called livian legion, dated probably around 4th century.

[Patrick Waterson]

I think there is more to the control and operation of a legion than either having or not having gaps between subunits.  Xenophon's Anabasis shows a predominantly hoplite force operating effectively in all types of terrain, usually with the assistance of peltasts and missilemen, and in one instance he deploys 100-man hoplite companies (lochoi) with gaps between them in mountainous terrain, mutual support being provided by the fact that they could move laterally along the slopes to support each other faster than their opponents could climb up or down.  Hoplite formations could operate with gaps if they wanted to: they usually did not because in normal circumstances it was suicidal.

The flexibility of the legion is described by Polybius is XVIII.32.10-12:

"The Roman order on the other hand is flexible: for every Roman, once armed and on the field, is equally well equipped for every place, time, or appearance of the enemy. He is, moreover, quite ready and needs to make no change, whether he is required to fight in the main body, or in a detachment, or in a single maniple, or even by himself. Therefore, as the individual members of the Roman force are so much more serviceable, their plans are also much more often attended by success than those of others."

Polybius ascribes the Roman flexibility to their all-purpose equipment, organisation and training, which he contrasts with the single-purpose orientation of the Macedonian phalangite.

From 505 BC the Republican Romans were fighting Sabines, Volsci and other hill-country peoples in addition to the Etruscans.  Dionysius of Halicarnassus refers to the Romans using 'hussois' (pila) in 503 BC, so we can put the transition to a manipular-type army in 504 or 503 BC, during the Sabine War of 505-503 BC.  The 'Livian' legion seems to have evolved between 437 and 394 BC, and the Polybian legion after 314 BC.  This was considered and explained at length in an article in Slingshot 292.

I think that intervals between manipula would allow not only the relief system we talked about, but even a faster and easier movement on battlefield of the deployed legion, which could manoeuvre in every battlefield, because manipula could avoid natural or artificial obstacles simply going around them.

Battlefields were usually selected precisely because they had no obstacles that needed to be manoeuvred around.  Generations of wargamers have obscured this essential point by cluttering their battlefield tables with terrain and obstacles that a real-life general would have avoided, and real battlefields usually had just a slope and/or a shallow river - or nothing.  The most important quality in an army (especially an Italian army, which usually lacked the impetus to defeat an opponent at first contact) during a pitched battle was staying-power, and this the Romans, with their line relief system, developed to a fine art.

In essence, the Roman legion was very undeveloped compared to the highly specialised, purpose-built, single-purpose Macedonian phalanx, and consequently stood no chance against it in frontal combat.  The great legion-against-phalanx victories (Beneventum, Cynoscephalae, Magnesia and Pydna) were all won when elephants broke the phalanx and the legions moved in to take advantage of the disruption.

[andrew881runner]

I think there is more to the control and operation of a legion than either having or not having gaps between subunits.  Xenophon's Anabasis shows a predominantly hoplite force operating effectively in all types of terrain, usually with the assistance of peltasts and missilemen, and in one instance he deploys 100-man hoplite companies (lochoi) with gaps between them in mountainous terrain, mutual support being provided by the fact that they could move laterally along the slopes to support each other faster than their opponents could climb up or down.  Hoplite formations could operate with gaps if they wanted to: they usually did not because in normal circumstances it was suicidal.

The flexibility of the legion is described by Polybius is XVIII.32.10-12:

"The Roman order on the other hand is flexible: for every Roman, once armed and on the field, is equally well equipped for every place, time, or appearance of the enemy. He is, moreover, quite ready and needs to make no change, whether he is required to fight in the main body, or in a detachment, or in a single maniple, or even by himself. Therefore, as the individual members of the Roman force are so much more serviceable, their plans are also much more often attended by success than those of others."

Polybius ascribes the Roman flexibility to their all-purpose equipment, organisation and training, which he contrasts with the single-purpose orientation of the Macedonian phalangite.

From 505 BC the Republican Romans were fighting Sabines, Volsci and other hill-country peoples in addition to the Etruscans.  Dionysius of Halicarnassus refers to the Romans using 'hussois' (pila) in 503 BC, so we can put the transition to a manipular-type army in 504 or 503 BC, during the Sabine War of 505-503 BC.  The 'Livian' legion seems to have evolved between 437 and 394 BC, and the Polybian legion after 314 BC.  This was considered and explained at length in an article in Slingshot 292.

I think that intervals between manipula would allow not only the relief system we talked about, but even a faster and easier movement on battlefield of the deployed legion, which could manoeuvre in every battlefield, because manipula could avoid natural or artificial obstacles simply going around them.

Battlefields were usually selected precisely because they had no obstacles that needed to be manoeuvred around.  Generations of wargamers have obscured this essential point by cluttering their battlefield tables with terrain and obstacles that a real-life general would have avoided, and real battlefields usually had just a slope and/or a shallow river - or nothing.  The most important quality in an army (especially an Italian army, which usually lacked the impetus to defeat an opponent at first contact) during a pitched battle was staying-power, and this the Romans, with their line relief system, developed to a fine art.

In essence, the Roman legion was very undeveloped compared to the highly specialised, purpose-built, single-purpose Macedonian phalanx, and consequently stood no chance against it in frontal combat.  The great legion-against-phalanx victories (Beneventum, Cynoscephalae, Magnesia and Pydna) were all won when elephants broke the phalanx and the legions moved in to take advantage of the disruption.

I don't agree about numbers. Firstly in 5th century Romans changed equipment, changing the round Clipeus together with typical hoplite phalanx with the oval scutum and introducing the use of  Pilum and reinforcements for shield after the defeat against gauls. Livian legion with antepilani and triarii rorari accensi seems to be dated to the middle of 4th century, 340/338 bc, at the time of the war against Latins. Then it evolved after the second war against samnites, particular after the big humiliation and defeat of 321 bc, when manipular legion was copied (before they used the servian system of centuriae, so we must suppose that now happens the shift from a hoplitic linear tactic, even if without typical hoplite equipment, towards a manipular tactic with gaps between companies). Finally throughou the 3rd century legion evolved newly in the sense of abolishing the wealth system which divided the men into different classes/ranks in battle towards a system based only on age and experience. Firstly even poor people were recruited. Polybian legion can be referred, by majority of opinions, to the beginning of second punic war (218) for sure, maybe before according to someone. So we are talking of late 3rd century for the typical Roman legion on 3 ranks we all imagine.
For what I know, at least Pydna and Magnesia were not lost because of elephants. In the first case because phalanx disrupted in an incoherent ground when it tried to pursue retreating Romans, in the case of Magnesia phalanx was already retreating under heavy missile fire, unable to attack back in the heavy slow 10 pike squares 50 x 32, when elephants gave the final hit. Ellenistic phalanges were all defeated with one exception with Pyrrus. Problem was not elephants but lacking of flexibility. Even the same throwing of Pila could be devastatimg against the close ranks in a pike phalanx.
As for the fact that battlefields had no obstacles, tell it to the Romans losing against samnites (not sabins) exactly because it was a montane ous terrain very well suited to the sabins manipular/cohortal tactics and poorly suited to the Romans who still used some type of linear deployment. The big shift happens during the war against samnites because these Sheepherds lived in a terrain with woods, hills, and mountains, more than the terrain Romans had fought so far (if you go to Rome you will see Hills, but mild and mainly plains). I guess they used the linear deployment of companies with gaps between companies well suited to avoid an obstacle and reform the line after it, Romans will copy and readapt to the relief system too in the manipular legion. Etruscans and other nations met by Romans still used phalanx system to the end of their days.

[Patrick Waterson]

I don't agree about numbers. Firstly in 5th century Romans changed equipment, changing the round Clipeus together with typical hoplite phalanx with the oval scutum and introducing the use of  Pilum and reinforcements for shield after the defeat against gauls.

Popular opinion on this point is wrong: the pilum is in use from 503 BC and the descriptions of battles from 486 BC indicate a missile-and-sword combination which is definitely manipular, not phalangite.  I can quote references if you like.

Livian legion with antepilani and triarii rorari accensi seems to be dated to the middle of 4th century, 340/338 bc, at the time of the war against Latins.

Actually triarii started out as camp guards and remained so until at least 437 BC; the first mention of triarii on the battlefield is in 394 BC. so we can date the Livian legion to this point or slightly earlier.  Livy's description is indeed dated to 340 BC but the legion he describes was in existence earlier.

Then it evolved after the second war against samnites, particular after the big humiliation and defeat of 321 bc, when manipular legion was copied (before they used the servian system of centuriae, so we must suppose that now happens the shift from a hoplitic linear tactic, even if without typical hoplite equipment, towards a manipular tactic with gaps between companies).

Again, this popular view is not supported by our sources.  The shift to the Polybian legion seems to have taken place after Poetilius' victory at Terracina in 314 BC, the reorganisation probably occurring around 311 BC or thereabouts.

Finally throughou the 3rd century legion evolved newly in the sense of abolishing the wealth system which divided the men into different classes/ranks in battle towards a system based only on age and experience. Firstly even poor people were recruited.

Is this a reference to the changes made by Caius Marius, usually assumed to begin around 107 BC?

Polybian legion can be referred, by majority of opinions, to the beginning of second punic war (218) for sure, maybe before according to someone. So we are talking of late 3rd century for the typical Roman legion on 3 ranks we all imagine.

Definitely before.  Source material is more valuable than opinions.

For what I know, at least Pydna and Magnesia were not lost because of elephants. In the first case because phalanx disrupted in an incoherent ground when it tried to pursue retreating Romans,

But Livy himself points out:

"On the right wing, where the battle had begun near the river, the consul brought up the elephants and the squadrons of the allies; and from this point the flight of the Macedonians first began." - XLIV.41.3

He further notes:

"The charge of the elephants was followed up by the allies of the Latin Name, who routed the left wing." - XLIV.41.5

Only after that does he note the "many scattered engagements which first threw into confusion and then disrupted the wavering phalanx"

in the case of Magnesia phalanx was already retreating under heavy missile fire, unable to attack back in the heavy slow 10 pike squares 50 x 32, when elephants gave the final hit.

Actually they were not retreating but standing, and continued to do so until the panicking elephants burst through, allowing the Romans to attack the broken formation.

Problem was not elephants but lacking of flexibility. Even the same throwing of Pila could be devastating against the close ranks in a pike phalanx.

Actually throwing pila at a pike formation's front had no noticeable effect: at Atrax, the Romans spent much of a day trying to defeat a pike phalanx frontally (it was plugging a gap in the city wall).  They achieved nothing, despite using pila, swords and everything they could think of.  See Livy XXXII.17, especially the following:

"When the Macedonians, in close array, stretched out before them their long spears against the target fence which was formed by the close position of their antagonists' shields, and when the Romans, after discharging their javelins without effect [pilis nequiquam emissis], drew their swords, these could neither press on to a closer combat, nor cut off the heads of the spears; [14] and if they did cut or break off any, the shaft, being sharp at the part where it was broken, filled up its place among the points of those which were unbroken, in a kind of palisade."

As for the fact that battlefields had no obstacles, tell it to the Romans losing against samnites (not sabins) exactly because it was a montane ous terrain very well suited to the sabins manipular/cohortal tactics and poorly suited to the Romans who still used some type of linear deployment. The big shift happens during the war against samnites because these Sheepherds lived in a terrain with woods, hills, and mountains, more than the terrain Romans had fought so far (if you go to Rome you will see Hills, but mild and mainly plains).

The Caudine Forks was a classic trap: my point is that when generals sought a battlefield as opposed to wandering into an ambush, they looked for something without annoying disruptive terrain, for example when Perseus was looking for a battlefield at Pydna:

"With such arguments his friends encouraged Perseus. So he pitched a camp and arranged his forces for battle, examining the field and distributing his commands, purposing to confront the Romans as soon as they came up. [5] The place afforded a plain for his phalanx, which required firm standing and smooth ground, and there were hills succeeding one another continuously, which gave his skirmishers and light-armed troops opportunity for retreat and flank attack. Moreover, through the middle of it ran the rivers Aeson and Leucus, which were not very deep at that time (for it was the latter end of summer), but were likely, nevertheless, to give the Romans considerable trouble." - Plutarch, Life of Aemilius Paulus 16.4-5

A very useful source on the early Roman army is Dionysius of Halicarnassus.  He provides much information that clarifies the rather confused story of legion development offered by Livy.  For some reason Dionysius has not been as well studied as Livy, which is a pity as he supplies much of the missing information and clarifies the point about when the Romans gave up the clipeus and adopted the scutum - it was when they became eisphoras, contributors, which is the correct meaning of Livy's stipendiarii.  The Romans adopted the scutum not when they received pay, but when private individuals financed state campaigns - a process begin during the first Sabine war of 505-503 BC.

If you order Slingshot 292 you will see the whole matter discussed and explained there in Rodger Williams' article.  This is the latest thinking on the early Roman legion.

[andrew881runner]

you should rewrite wikipedia's page about Roman legion.

[RobertGargan]

Dionysius of Halicarnassus wrote his history of Rome in the late 1st century BC, if not AD.  He could have based his narrative on heroic stories to provide Rome with a historic past to inform the Greek world.  I am not sure he described the move from the hoplite phalanx to the deployment of the more flexible manipular formation - which may have been a response to the Samnite wars in the 3rd century BC.
Robert

[Erpingham]

you should rewrite wikipedia's page about Roman legion.

Alas, it would be a classic case of OR - original research.  Wikipedia should be based on published sources subject to academic scutiny (no laughing at the back ), and a Slingshot article wouldn't count.

[andrew881runner]

you should rewrite wikipedia's page about Roman legion.

Alas, it would be a classic case of OR - original research.  Wikipedia should be based on published sources subject to academic scutiny (no laughing at the back ), and a Slingshot article wouldn't count.

yes, exactly, it does not count. Wikipedia is based on published sources, if you scroll to end of the page you will notice them.

[aligern]

I'll add my two pence worth, if I may.
Having a mix of shield types organised by shape appears to be a standard Italian mode of operation. The Romans are the result of a mix of Latins and Etruscans......and Trojans if you take a very literal view of sources:-)). 
In Italy there are illustrations of soldiers in Greek inspired armour, or what we take to be Greek inspired armour , with Italian weapons, throwing spears , early pila etc.  I say Greek inspired armour because we have a very Hellenocentric view of armour styles. If something was invented in Egypt (the linothorax) or  in Caria (men of bronze) we see it as Greek.  In Italy we see a mix of styles, Celtic, native Italian, Spanish, if disc cuirasses are from there or are they from Italy to Spain or mutually independent?  That gives rise to what appears to be aspides (hoplite shields) being used by Campanians and Etruscans. however, I wonder if this indicates the adoption of a foreign shield type into an Italian context, simply  replacing the rimless Italian round shield with the aspis and keeping the Italian missile weapon. This adoption could well take place at the same time as the Greeks are using the aspis/ hoplon with a pair of javelins, perhaps interchangeably with a thrusting spear.
Generally the Greek colonies in Italy were established early.  They will have brought Greek methods of warfare, but they appear to adapt to Italian conditions, so Capuans become famous heavy cavalry, Tarantines light. Unfortunately I am unaware of Contemporary sources that show how the infantry of these Greek colonies fought. I except Sicily, though I wonder whether the sources would tell us if Sicilian Greeks were throwing or thrusting their spears (personally I would suggest that the Sicels and Sicans were not as influential on the Siciliot Greeks).
So may I suggest that the Roman situation is not some simple move from being spear armed hoplites to being javelin armed scutatoi, but simply a change of shield type for those already using a throwing a weapon.

Roy