The mechanism of Roman line relief

[Patrick Waterson]

The men 'pushing with their knees' at Argentoratum are Alemanni, and probably Alemanni cavalry, as the description occurs during the narrative of the cavalry action.

The use of the knee to brace the shield was a defensive measure, as described in Cornelius Nepos' Life of Chabrias, I.2

Chabrias the Athenian was also numbered among the most eminent generals, and performed many acts worthy or record. But of these the most famous is his manoeuvre in the battle which he fought near Thebes, when he had gone to the relief of the Boeotians; for in that engagement, when the great general Agesilaus felt sure of victory, and the mercenary troops had been put to flight by him, Chabrias forbade the rest of his phalanx to quit their ground, and instructed them to receive the attack of the enemy with the knee placed firmly against the shield, and the spear stretched out. Agesilaus, observing this new plan, did not dare to advance, and called off his men, as they were rushing forward, with sound of trumpet. This device was so extolled by fame throughout Greece, that Chabrias chose to have the statue, which was erected to him at the public charge by the Athenians in the forum, made in that posture.

One may note this was a 'new plan' (novum), an improvisation, not a recognised manoeuvre, and was above all defensive in nature.

Conversely, in Ammianus' account of Argentoratum the 'knee pressure' comes in XVI.12.37, before the infantry close to combat in XVI.12.42, the interim period being occupied in a missile exchange (XVI.12.36) and the cavalry action (XVI.12.37-41).  I would read this as the Alemanni 'spurring' on their cavalry without having spurs, urging their mounts on by knee pressure to force back their Roman cavalry counterparts (and perhaps hold their attention and position while the Alemanni light infantry went about their business of horse-belly-slitting).

On the subject of Cimbri and Teutones, these seem to have been Germans rather than Gauls, and the use of a chain to keep the front rank level suggests a deliberate rather than impetuous advance.  Gallic impetuosity seems to have been containable until the leaders wished it unleashed, missile-maddened individuals at Telamon and Olympia notwithstanding.  I am still looking for an explicit description of a Gallic charge outside Caesar - our sources seem uninterested in the actual mechanics of closure.

[aligern]

Aha, at last we come to the definition of what is a Gaul.

The Cimbri and Teutones have been characcterised as Gallic culture tribes abandoning Germany as the future Germans of Tacitus move into the country.
A sub tribe that is travelling with them moves in with the Helvetii and  is not distinguished as Germans  by Caesar, though for him being German might just mean Trans Rhenane.
Artefacts such as the Gundestrup cauldron that are found in the Cimbric area might  well argue for a developed Celtic culture.
The names of the leaders of the Cimbri and Teutones are Celtic.
The animal headed headdresses  and description of their tactics happily fits with Celtic
The abandonment of Celtic sites in Germany such as the Heuneberg argues for a southward migration of the Celts away from German pressure.


None of the above is absolute proof, but on balance I'd see the C and T as more Celtic than German if the distinction is meaningful.. and I think it might be meaningful.

Roy

[aligern]

This is the section from Ammianus: So, when the call to battle had been regularly given on both sides by the notes of the trumpeters, they began the fight with might and main; for a time missiles were hurled, and then the Germans, running forward with more haste than discretion, and wielding their weapons in their right hands, flew upon our cavalry squadrons; and as they gnashed their teeth hideously and raged beyond their usual manner, their flowing hair made a terrible sight, and a kind of madness shone from their eyes. Against them our soldiers resolutely protected their heads with the barriers of their shields, and with sword thrusts or by hurling darts threatened them with death and greatly terrified them. 37 And when in the very crisis of the battle the cavalry formed massed squadrons valiantly and the infantry stoutly protected their flanks by making a front of p285their bucklers joined fast together, clouds of thick dust arose. Then there were various manoeuvres, as our men now stood fast and now gave ground, and some of the most skilful warriors among the savages by the pressure of their knees tried to force their enemy back; but with extreme determination they came to hand-to‑hand fighting, shield-boss pushed against shield, and the sky re-echoed with the loud cries of the victors or of the falling. And although our left wing, marching in close formation had driven back by main force the onrushing hordes of Germans and was advancing with shouts into the midst of the savages, our cavalry, which held the right wing, unexpectedly broke ranks and fled; but while the foremost of these fugitives hindered the hindmost, finding themselves sheltered in the bosom of the legions, they halted, and renewed the battle. 38 Now that had happened for the reason that while the order of their lines was being re-established, the cavalry in coat-of‑mail, seeing their leader slightly wounded and one of their companions slipping over the neck of his horse, which had collapsed under the weight of his armour, scattered in whatever direction they could; the cavalry would have caused complete confusion by trampling the infantry underfoot, had not the latter, who were packed close together and intertwined one with the other, held their ground without stirring. So, when Caesar had seen from a distance that the cavalry were looking for nothing except safety in flight, he spurred on his horse and held them back like a kind of barrier. 39 On recognising him by the purple ensign of a dragon, fitted to the top of a very long lance and spreading p287out like the slough of a serpent, the tribune of one of the squadrons stopped, and pale and struck with fear rode back to renew the battle. 40 Whereupon Caesar, as is the custom to do in times of panic, rebuked them mildly and said: "Whither are we fleeing, my most valiant men? Do you know not that flight never leads to safety, but shows the folly of a useless effort? Let us return to our companions, to be at least sharers in their coming glory, if it is without consideration that we are abandoning them as they fight for their country." 41 By his tactful way of saying this he recalled them all to perform their duty as soldiers, following (though with some difference) the example of Sulla of old. For when he had led out his forces against Mithradates' general Archelaus and was being exhausted by the heat of battle and deserted by all his men, he rushed to the front rank, caught up a standard, flung it towards the enemy, and cried: "Go your way, you who were chosen to be companions of my dangers, and to those who ask you where I, your general, was left, answer truthfully: 'Fighting along in Boeotia, and shedding his blood for all of us.' "

  Seems to me that its shield-boss against shield boss and that the Germans are indeed PUSHING with their knees. 
Roy

[Patrick Waterson]

The 'pushing with the knees' is 'obnixi genibus', whereas Nepos in his Life of Chabrias has 'obnixo genu scuto', unambiguously 'with the knee bracing the shield'.  Ammianus conspicuously has 'genibus', the plural, and a complete absence of any shield.

Further, the structure of the narrative points to the 'knees' occurring during the cavalry engagement.  The passage seems to have been partly mistranslated.

And when in the very crisis of the battle the cavalry formed massed squadrons valiantly and the infantry stoutly protected their flanks [actually 'et muniret latera sua firmius pedes' = and [the cavalry] guarded their [own] flanks as firmly as infantry; 'firmius' is a comparative, 'as firm as'] by making a front of their bucklers joined fast together [frontem artissimus conserens parmis], clouds of thick dust arose. Then there were various manœuvres [discursus = movements rather than manoeuvres], as our men now stood fast and now gave ground, and some of the most skilful warriors among the savages by the pressure of their knees tried to force their enemy back; but with extreme determination they came to hand-to-hand fighting [dexterae dexteris miscebantur = they interspersed, right side to right side], shield-boss pushed against shield, and the sky re-echoed with the loud cries of the victors or of the falling.

Roman cavalry and infantry both used bossed shields, but legionaries did not use the parma.  Ammianus seems to be saying here that the Roman cavalry:

1) Joined their squadrons into a single line
2) Thus secured the flanks of each squadron as firmly as infantry
3) Put their shields up facing the enemy
4) Movements then occurred, some Romans giving ground and some barbarians using knee pressure to gain it
5) Finally interpenetration occurred so that each side's cavalrymen faced unshielded foes on their right and shielded on their left.

This makes a coherent and credible sequence of events that has suffered at the hands of translators and given rise to misunderstandings.

It also suggests that the Roman clibanarii in mid-4th century Gaul used standard cavalry weapons and shield rather than lances, but that is a different discussion.

[aligern]

Must say I cannot see how cavalry push with their knees. The actions of cavalry and infantry are interspersed in the narrative hence I believe that the boss to boss action and knee pushing is inafantry action.
Roy

[Patrick Waterson]

Must say I cannot see how cavalry push with their knees.
Roy

Ask the horse. 

The infantry action begins with XVI.12.42:

Then the Alamanni, having beaten and scattered our cavalry, charged upon the front line of the infantry, supposing that their courage to resist was now lost and that they would therefore drive them back.

The infantry action went thus, with nobody using their knees except to drop to:

But as soon as they came to close quarters, the contest continued a long time on equal terms. For the Cornuti and the Bracchiati, toughened by long experience in fighting, at once intimidated them by their gestures, and raised their mighty battle-cry. This shout in the very heat of  combat rises from a low murmur and gradually grows louder, like waves dashing against the cliffs. Then a cloud of hissing javelins flew hither and thither, the dust arose with steady motion on both sides and hid the view, so that weapon struck blindly on weapon and body against body.  But the savages, thrown into disorder by their violence and anger, flamed up like fire, and hacked with repeated strokes of their swords at the close-jointed array of shields, which protected our men like a tortoise-formation.  On learning this, the Batavians, with the "Kings" [Reges] (a formidable band) came at the double quick to aid their comrades and (if fate would assist) to rescue them, girt about as they were, from the instant of dire need; and as their trumpets pealed savagely, they fought with all their powers.  But the Alamanni, who enter eagerly into wars, made all the greater effort, as if to destroy utterly everything in their way by a kind of fit of rage. Yet darts and javelins did not cease to fly, with showers of iron-tipped arrows, although at close quarters also blade clashed on blade and breastplates were cleft with the sword; the wounded too, before all their blood was shed, rose up to some more conspicuous deed of daring.  For in a way the combatants were evenly matched; the Alamanni were stronger and taller, our soldiers disciplined by long practice; they were savage and uncontrollable, our men quiet and wary, these relying on their courage, while the Germans presumed upon their huge size.  Yet frequently the Roman, driven from his post by the weight of armed men, rose up again; and the savage, with his legs giving way from fatigue, would drop on his bended left knee and even thus attack his foe, a proof of extreme resolution.

Observe the different character of the fighting: missiles continue to fly during the melee, movements are minimal and fatigue or overbearing puts down opponents.

[Erpingham]

Somethings don't change though - the barbarians are all tall, strong and in a rage, while the Romans fight in a disciplined way.  I'm sure the warrior falling on one knee with exhaustion but continuing to fight is an artistic image that carries back to classical Greek art too.  Ammianus knew his classics (and his audience).

[aligern]

Eureka!
The Roman, driven from his post by the weight of armed men rose up again.  Of course, one single Roman is not going to be driven back or this contest of overlapped shields w,oils disintegrate. This must be a literary description of Romans retiring exhausted to rest and then coming back to the fray again.

Roy

[Patrick Waterson]

Sloppy translation, I am afraid.  'Pulsus loco Romanus' means 'A Roman, knocked down in his place' not driven from it, which would be 'ex pulsus loco Romanus' or 'pulsus ex loco Romanus'.

Somethings don't change though - the barbarians are all tall, strong and in a rage, while the Romans fight in a disciplined way.  I'm sure the warrior falling on one knee with exhaustion but continuing to fight is an artistic image that carries back to classical Greek art too.  Ammianus knew his classics (and his audience).

There are simple reasons for this: Romans were disciplined, Alemanni were not.  Alemanni were tall, Romans were not.  And one wonders whence came the original inspiration for classical art, if not in actual occurrences.   That said, Ammianus does like his heroic atmosphere, though I doubt that it affects the accuracy of his narrative.

One point we may note is that line relief does not seem to be part of the process any longer.  The crux of the action occurs when the German kings, with their select followers, plough through their own side's faltering ranks to charge the Roman centre.

And so there suddenly leaped forth a fiery band of nobles, among whom even the kings fought, and with the common warriors following they fell upon our lines before the rest; and opening up a path for themselves [et iter sibi aperiendo = and needing to open a way for themselves] they got as far as [pervenit = reached, arrived at] the legion of the Primani, stationed in the centre in a strong formation called praetorian camp [quae confirmatio castra praetoria dicitatur = which was said to be as secure as a praetorian camp]; there our soldiers, closely packed and in fully-manned lines [densior et ordinibus frequens = impenetrable and in steady formation] stood their ground fast and firm, like towers, and renewed the battle with greater vigour; and being intent upon avoiding wounds, they protected themselves like murmillos, and with drawn swords pierced the enemy's sides, left bare by their frenzied rage.  But the enemy strove to lavish their lives for victory and kept trying to break the fabric of our line. But as they fell in uninterrupted succession, and the Romans now laid them low with greater confidence, fresh savages took the places of the slain; but when they heard the frequent groans of the dying, they were overcome with panic and lost their courage.  Worn out at last by so many calamities, and now being eager for flight alone, over various paths they made haste with all speed to get away, just as sailors and passengers hurry to be cast up on land out of the midst of the billows of a raging sea, no matter where the wind has carried them; and anyone there present will admit that it was a means of escape more prayed for than expected.  Moreover, the gracious will of an appeased deity was on our side, and our soldiers slashed the backs of the fugitives; when sometimes their swords were bent, and no weapons were at hand for dealing blows, they seized their javelins [tela = weapons] from the savages themselves and sank them into their vitals; and not one of those who dealt these wounds could with their blood glut his rage or satiate his right hand by continual slaughter, or take pity on a suppliant and leave him. - Ammianus XVI.12.49-52

Ammianus further describes the Alemanni being followed up down-slope to the river, where they suffered even heavier losses.  Noteworthy is the bending of Roman swords with prolonged use (18th century bayonets tended to do the same) and the fighting technique of the Primani - the stab to the opponent's unguarded side and the weaponry bending with use could both come from a description of Barrel's and Munro's regiments at Culloden.  It was not only Gauls who found their metallurgy sometimes wanting on the battlefield.

Patrick

[Erpingham]

There are simple reasons for this: Romans were disciplined, Alemanni were not.  Alemanni were tall, Romans were not.  And one wonders whence came the original inspiration for classical art, if not in actual occurrences.   That said, Ammianus does like his heroic atmosphere, though I doubt that it affects the accuracy of his narrative.

Patrick

I would caution taking every detail as literally true.  Ammianus is a good observer, but it seems to me he applies his not inconsiderable talents to conjur up a classical battlepiece.  The height differential may have been considerable in the days of the Republic but it was less so in the late Empire - the Roman army is not all lads from the urban slums anymore.  No doubt men did go down on one knee but was it often?  And did the Romans still use short stabbing swords at this stage?

So, on the main manoeuvers, I'd take A pretty seriously.  Even on some of the tactics - the cavalry closing up like infantry, for example, or the infantry clearly in very close order (I'm tempted to suggest foulkon except we'd need another debate to unpack the term ).  But the striving heroic combat stuff looks like a literary polish.  And before I'm accused of being over literary, I would point to John Keegan's analysis of battlepieces in modern military history and how they evoke feel as much as they deliver facts (Face of Battle, Ch.1).

[aligern]

Methought that Philip Rance had providedbthenlast word on the Foulkon?

https://web.duke.edu/classics/grbs/FTexts/44/Rance2.pdf

Roy

[Erpingham]

Methought that Philip Rance had providedbthenlast word on the Foulkon?

Roy

I recall it as being pretty comprehensive but I can't remember if he thought the order Ammianus was describing was a Foulkon.  If I get a chance, I'll relook at it and find out, unless someone knows the answer?

[Patrick Waterson]

Moving off at a slight tangent (and just in passing mentioning Napier's history of the Peninsular War as a source that combines heroic action with usable accuracy), the apparent lack of line relief (but possible unit relief when the Batavi and Reges move to get the Cornuti and Bracchiati out of a jam) at Argentoratum may match up with the legion reorganisation that happened around the early 4th century AD.

The traditional legion was about 5,000-6,000 strong and fought in three lines (Caesar), or two plus 'triarii' (Vegetius).  Each line in a three-line legion would contain 1,600-2,000 men.  It would appear that during the legion reorganisation the number of legions roughly tripled, while individual legion strength went down to maybe 1,200-1,500 men (authorised strength may have been a bit higher).

Hypothesis: instead of a 5/6,000-man three-line legion using line relief the new system deployed a single-line 1,600-2,000-man (at full strength; usually less when fielded) legion without line relief, but which may have exchanged fresh reserve formations for tired/endangered front line units, basically taking the Roman system back full circle to its earliest days except that now small legions formed the basic 'unit of relief' rather than maniples.  The new small legion occupied the same frontage as the old large legion, but was all 'up front', six ranks deep.  A second line, probably of auxilia, would stand ready to go to the assistance of any legion in trouble, perhaps at the ratio of one auxilium giving cover for one legion.

This is still somewhat hypothetical, and in need of further evidence one way or the other, but is aired here because it seems to fit and looks like a possible tail-end development of the original subject.

Patrick

[Erpingham]

Interesting thoughts.  I'd be interested in views as to whether there was a deliberate division of legions into three in the early fourth century, as opposed to a period when legionary detachments had left the empire covered in bits of legion and this was regularised.  What's the last reference we have prior to 4th century of whole line relief, as opposed to smaller units swapping with one another?  This may help judge whether line relief went out with the old legions.

[Patrick Waterson]

For most of the period we have to rely on inference, e.g. Diocletian's Joviani and Herculiani are given as c.6,000 strong AD c.300 (Vegetius I.16: "We formerly had two legions in lllyricum, consisting of six thousand men each"); Ammianus at the siege of Amida (AD 359) has "seven legions, a heterogenous crowd of strangers and citizens of both sexes and a few other troops, amounting in all to 20,000 souls," suggesting the legions were of no great size, and at Argentoratum (AD 357) Julian has 13,000 troops, some of whom are cavalry, while five infantry formations (Cornuti, Bracchiati, Batavi, Reges, Primani) from the right and centre are named.  Formations on the left and possibly some in the centre and reserve are not named, so perhaps ten or more infantry formations may have been fielded, and certainly more than five.  Allowing for some being 500-man auxilia, there is still not much manpower left over for the legions.

The Notitia Dignitatum of AD 395 or later has a profusion of units, the west alone having 12 'palatini' and 32 'comitatenses' legions, whereas traditionally (before the reorganisation) the Empire had maintained around 14 legions in the west: 3 legions in Britain, 4-5 in Gaul, 1 in Spain and 1 (praetorians) in Italy, plus 2-5 in Illyria.  Jumping from 14 to 44 implies three times as many legions, and given Ammianus' figures above, also suggests the new legions were at about 1/3 strength.  The west also has 65 auxilia palatini.  There are also 17 'pseudocomitatenses' whose role and status is unclear, but they are listed where we might expect auxilia comitatenses, a category conspicuous by its absence.

Over time, legions had sent vexillations (detachments) to various other theatres to meet emergencies, and some of these vexillations seem not to have returned to the parent legions.  It is quite likely that they were regularised as new legions (and it is possible but by no means certain that the 'seniores' and 'iuniores' might represent an original legion and its vexillated 'offspring', though as the 'senior' and 'iunior' legion are occasionally listed together in the Notitia and some auxilia bear these designations this is not an infallible supposition).  However this would leave imbalanced legions (some at c.4,000 men; others at c.2,000) so it looks as if a deliberate decision was taken to divide up all legions, not just those with alienated vexillations.  Elite legions such as the Joviani and Herculiani as far as I know stayed together rather than emitting vexillations, which would also suggest a deliberate readjustment.

Whether this coincided with the end of line relief is harder to judge owing to the paucity of battle accounts mentioning such details, though the idea of looking for the last known mention of line relief is a good one.  My impression (which may be incorrect) is that the last explicit reference is in Caesar's description of Pharsalus (48 BC).  Tacitus describes the battles at Bedriacum in AD 69 in some detail, but is more concerned about which legion did what than about tactical procedures.  Historians between Tacitus and Ammianus are not noted for attention to military detail, which is why we surmise much from Trajan's column and argue over who created the first Roman heavy cavalry rather than having a source which tells us what we need to know.  From memory (and I shall have to track this down) Marcus Aurelius committed multiple lines against invading Alemanni, and Decius against the Goths and Scythians at Abritus (AD 251), but this will mean a trawl through Dio, Zonaras et. al. when I get the time.

Ergo, the idea that line relief went out with the new smaller legion remains hypothetical, though Vegetius (writing in the 4th century AD) uses a basic six deep deployment and refers to multiple lines as a feature of the 'ancient legion'.  This may be as close as we get.  There is however one perhaps useful pointer.

Traditionally, a legion (5,000-man) deployed on a front of about 200 yards, as far as we can establish.  This would be commensurate with three lines each containing c.1,600 men deployed 200 wide and 8 deep.  Vegetius uses what appears to be a standard army frontage of 1,656 men and a six deep deployment, which may be just a clever way of fitting nearly 10,000 men into a quick-and-dirty deployment or it may indicate that the army was usually expected to deploy six deep.  If so, then a 1,200-man 'new legion' could deploy on a 200 yard frontage six men deep, hence covering the same frontage as a traditional (5-6,000-man legion).  A 1,600-man 'new legion' could deploy eight deep on the same frontage.

More importantly, a six deep deployment leaves no realistic possibility of line relief (although there remains a theoretical possibility of rank relief) so there may have been a recognition or belief that against the opponents currently faced by the Empire three lines constituted overkill and one line - perhaps backed by a reserve line, as seems to have been the case at Argentoratum - sufficed for ordinary battlefield needs.  Rather than have a traditional legion deploy on a frontage three times the usual width, the new system seems to have three new legions, each on the frontage of an old legion.  This new deployment system (if it was indeed such) would go some way to explaining why Julian with 13,000 men at Argentoratum was able to match the frontage of 35,000 Alemanni.