Pharsalus 48 BC

[Duncan Head]

Looking at the Cavalry, was there legionary cavalry in this period?

The general belief is that no, there weren't. Caesar never mentions them in either the Gallic or Civil campaigns, and McCall's Cavalry of the Roman Republic sees the last mention of citizen cavalry well before the "Marian reform".

[Patrick Waterson]

True: then again, we do not get a TO&E for the 'Marian' legion until the early Empire, by which time the legion had 120 integral cavalry and not one trooper more, with any additional cavalry being supplied in the form of separate 512-man alae.  We can of course attempt to retrofit this arrangement into Caesar's period, and assume that his 1,000 Gallic and German cavalry at Pharsalus comprised two such alae, but attempting to shoehorn Pompey's contingents into the system - with the possible exception of his Roman cavalry from Egypt - does not work.

Caesar gives us a few clues in Civil War III.34:

Caesar having joined Antony's army, and recalled the legion he had left at Oricum to guard the sea-coast, judged it necessary to advance farther into the country, and possess himself of the more distant provinces. At the same time,deputies arrived from Thessaly and Aetolia with assurances of submission from all the states in those parts, provided he would send troops to defend them. Accordingly he despatched L. Cassius Longinus, with a legion of new levies, called the twenty-seventh, and two hundred horse, into Thessaly; and C. Calvissius Sabinus, with five cohorts, and some cavalry [pauicisque equitibus = and a few cavalry], into Aetolia; charging them in a particular manner, as those provinces lay the nearest to his camp, that they would take care to furnish him with corn. He likewise ordered Cn. Domitius Calvinus, with the eleventh and twelfth legions, and five hundred horse, to march into Macedonia: for Menedemus, the principal man of that country, having come ambassador to Caesar, had assured him of the affection of the province.

We observe that 700+ cavalry are thus allocated to three and a half legions, with 200-250 cavalry per legion.  While Caesar does not tell us whether they came out of his original 1,000 or were additional to these, what he is telling us is that it still seems to have been customary to send 200-300 cavalry with a legion.

For this reason, I am inclined to suppose that Pompey had recruited approximately 300 cavalry for each of his approximate legions; if so, it neatly makes up 3,300 of the 3,400-horseman deficiency in Caesar's account, as mentioned.  Whether the cavalry were ever actually bundled with the legions as opposed to simply recruited to make up the right numbers seems to me to be a moot point.  Assuming this is what Pompey did, of course: it remains a hypothesis at present.

I suspect that legionary cavalry allocation and Roman cavalry organisation generally were somewhat in flux, particularly as the ongoing Civil War meant that protagonists would to a considerable extent have been governed by what they could get as opposed to what they may have wanted to raise and/or organise.

[Jim Webster]

Interesting your having Caesar allocate a number of allied cavalry per legion is very similar to what Steve has come up with having commanders allocate a number of allied light infantry per legion

[Patrick Waterson]

Indeed.  The difference seems to be, as far as I can extract from Polybius' Book VI organisation and Caesar's Gallic War II.7.1, II.10.1, II.19.4 and VII.40.5, that while cavalry was allocated on a temporary or enduring basis to legions, missile troops such as Cretans and Numidians were not, but were directly under the C-in-C, often employed as an adjunct to the combined cavalry.  Integral skirmishing capability for the legion was provided by its velites (up to the Marian reforms) and thereafter by integral ferentarii, artillery and/or lanciarii, as far as we (that is, I) can judge.

The early Imperial period saw the Cretans, Numidians etc. being fielded as auxiliary cohorts, which was probably the formalisation of what may then have been the de facto situation.

The problem with Steven's analysis is that he appears to leave out the velites entirely when considering the Polybian legion, and to assume that the various archers and slingers at Pharsalus were an integral part of the legionary strength and organisation as opposed to being allied or co-opted contingents in separate units.  In essence he is substituting them for velites.

I think his basic premise - that Roman Republican organisation was founded on Pythagorean numerical principles - may have validity, but unfortunately his approach seems to centre on crunching the numbers rather than substantiating them, and in the process deciding that Polybius completely misunderstood the Roman legion.  If we have to discard Polybius in order for Steven's system to work, then one or the other must be wrong, and we do not seem to have independent evidence of Polybius' description of the legion of his day being incorrect.

[Duncan Head]

True: then again, we do not get a TO&E for the 'Marian' legion until the early Empire, by which time the legion had 120 integral cavalry and not one trooper more

Though Ilkka Syvanne argues for 512 cavalry per Imperial legion 

[Patrick Waterson]

Do his arguments look reasonable (not having seen them)?

[Duncan Head]

I've only noticed it in glancing through the book, haven't read it yet. I do recall he rejects Josephus' 120 as this is merely described as the number of horsemen accompanying a legion on the march, which, I S suggests, need not be the whole strength, others being part of the army's advance guard, flank pickets, etc. But I simply don't agree with his understanding of the Greek. In B.J. 3.120, "eipeto d'auto to idion tou taymatos ippikon: idioi gar hekastou taymatos eikosi pros tois hekaton hippeis" does seem to me to mean, as in the translation at Perseus, that there were 120 cavalry who belonged to each legion.

[Patrick Waterson]

... I simply don't agree with his understanding of the Greek. In B.J. 3.120, "eipeto d'auto to idion tou taymatos ippikon: idioi gar hekastou taymatos eikosi pros tois hekaton hippeis" does seem to me to mean, as in the translation at Perseus, that there were 120 cavalry who belonged to each legion.

Yes, Josephus' use of idion/idioi does look as if he is specifying the legion's 120-strong 'tagma' of cavalry as an integral entitiy from an organisational standpoint.  Given that he is describing, in some detail, a Roman force on the march, were there additional outriders of specifically legionary cavalry, I for one would have expected him to mention them.

And would a legion actually need more than 120 cavalry to do its messaging and escorting if it could also when needed be accompanied by an ala of 'real' cavalry, perhaps as part of a larger force?  I suspect Ilkka is off on another of his flights of fancy here, but await your judgement when you do get around to reading through the relevant bit.

As a final thought, I do not recall any excavations of Roman marching camps giving rise to suggestions that Josephus under-represented the legion's cavalry component.

[Duncan Head]

Right, having now got to that bit in the book, Syvanne says (p.8 )

According to John Lydus (De Magistr. I.16), when Marius formed his legions the legions consisted of 6,000 infantry and 600 cavalry, and this seems to have been the model according to which Augustus formed his imperial legions. ... In most cases, the figure of 600 horsemen probably included the servants attached to the cavalry. My educated guess is that the regular fighting (paper) strength of the cavalry detachment was an ala of 512 horsemen plus the supernumerarii and servants(5).

(Fn.5: The usual mistake is to assign legions only 120 (=128) horsemen on the basis of Josephus' statement that 120 horsemen accompanied each legion in the marching formation in 67 AD. In truth, Josephus does not really say anything about the size of the actual cavalry component of each legion, but refers only to the horsemen accompanying each legion in the marching formation. Josephus does state that there were other horsemen in the front and rear and it is easy to see that when one includes these in the numbers the likely strength of the legionary cavalry was still the traditional 512 horsemen. I have discussed these things in three research papers, which will be published later.)

However, it is possible that there were actually three different types of cavalry units attached to the legion in the third century. Ps.-Hyginus (5.30) doesn't include any equites legionis for the three legions, but mentions 1,600 vexillari legionum. This figure is consistent with the 500-man turmae of mounted archers, 500-man vexillationes, and 600-man alae mentioned by John Lydus (De Magistr. I.46). Hence the possibility that the legion could have included three different types of cavalry detachments. The only real anomaly is Vegetius who claims that each legion was accompanied by an even greater number of horsemen...

The relevance for the Pharsalus discussion is of course the suggestion that Marius' legions had an integral 600-man cavalry component, which presumably means that the legions at Pharsalus would have (or at least, according to a paper organisation that may or may not have fully applied during civil war, should have) a similar component. But relying on John Lydus, really?

Ioannes Lydus, or John the Lydian, wrote De Magistratibus Populi Romani in Greek (the original title is Peri Archon tes Romaion Politeias) in the 6th century. There is a French translation available at http://bcs.fltr.ucl.ac.be/Lydus/LydTrI.html; the Greek original in a pdf of a 19th-century edition is available from http://www.documentacatholicaomnia.eu/04z/z_0490-0578__Joannes_Lydus_Laurentius__De_Magistratibus_Populi_Romani_%28CSHB_%29__GR.pdf.html I know of no English version.

At I.16, Lydus says that Romulus added 3,000 infantry and 300 cavalry from the Sabines to his original Roman force of the same strength,

... so there were 6,000 infantry and 600 cavalry. This number was kept up later by Marius, when he created the so-called legions (which means "picked troops").

At I.46, we are told that the soldiers were organised into units, at a date in the 4th century BC:

so there were units of 300 men with shields (aspidiotai) called "cohorts", alae (that is, ilai) of 600 horsemen, vexillations of 500 horsemen, turmae of 500 mounted archers (that's in the French edition; Niebuhr's 19th-century text has just "vexillations of 500  mounted archers". But the longer version fits the following list) and legions formed of 6,000 infantry and the cavalry cited above.

The subdivisions of the legion are:
alae of 600 cavalry
vexillationes of 500 cavalry
turmae of 500 horse-archers
legiones of  6000 infantry
...

Lydus clearly has some dodgy ideas about chronology, and some of his unit strengths look so unlikely - cohorts of 300 infantry? would a unit of 500 horsemen ever be called a turma? - that it does not seem safe to accept any of them.

And with that finally completed, I can return to New Year's Eve. Happy New Year, all.

[Duncan Head]

Incidentally here is a thesis on the Roman legionary cavalry which just about sums up the "orthodox" view - he seems to take the number of 120 more or less for granted.

From what he says about Inchtuthil, the fortress archaeology does not seem to provide a clear answer as to the numbers of horsemen catered for in legionary camps - though it does look as if you might have trouble fitting 500 in.

Edit: Sorry,wrong link - same author and subject, different paper. I was looking for the U of Hawaii PhD dissertation "The Legionary Horsemen: an essay on the equites legionis and equites promoti". Can't find that online any more.

[Patrick Waterson]

Thanks, Duncan: it seems reasonably safe to assume that Josephus may have been a better source than Lydus, not least because he was a contemporary, and that Lydus' cohort/ala strengths are to say the least questionable, at least when trying to infer what a 1st century BC (or AD) legion may have fielded.

Curiously enough, Polybius XI.23.1, with its three-maniple 'koortis', suggests a cohort of about 300 men (the three maniples presumably being 2x120 and 1x60), but this is a singular instance which is at variance with later cohort strengths, e.g. in Vegetius.  I also suspect that the troops in 'cohorts' at Ilipa were not legionaries as such but rather extraordinarii, and three maniples of 120 would give a 'koortis' of 360, while three such 'cohorts' would add up to 1,080 men, which is close enough to the 1,000-ish extraordinarii we would expect from a 5,000-ish man Italian allied infantry formation of the Punic Wars.  Lydus might conceivably have picked this up from somewhere and mistaken it for the norm - at least, that is my conjecture.


We can probably stick with the traditional Josephus-noted figure of 120 cavalry for the Early Imperial legion, whether they were messengers, scouts, bodyguards for the legate or all three.  Exactly how much cavalry would have been allocated/assigned to a 1st century BC legion is another question, and it is noteworthy that Caesar tends to use cavalry as a separate arm.  In the 54 BC rebellion none of the overwintering legions appear to have any cavalry whatsoever, and Caesar is in the habit of drawing on the Gallic tribes for his cavalry.  However the cavalry/infantry ratio, where he mentions this, might allow some provisional conclusions.

In BG V.2.4 Caesar takes four legions 'expeditis' and 800 cavalry on his punitive expedition against the Treveri.  This is 200 cavalry per legion, one of our traditional Livian/Polybian allocations, or at least ratios.  In I.15.1 4,000 cavalry raised from Narbonensis and Gallic allies accompany his five legions (at least in I.10.3 he has five), which is about 800 cavalry per legion, and the same number are raised or gathered prior to the second invasion of Britain, but Caesar leaves 2,000 with Labienus' three legions while taking 2,000 with his five, thus providing 400 cavalry per legion for his invasion force.  In short, where Caesar is concerned there seems to be no fixed legionary cavalry allowance, but from incidental mentions in the Gallic War and Civil War, it looks as if he tends to allocate at least 200 cavalry per legion, or at least keep cavalry amounting to at least this total, and sometimes considerably more than that.


I would suggest this reflects standard 1st century BC Roman practice.  Unfortunately there is not a lot of additional material on this point: Sallust tends to avoid mentioning army strengths, although he does note in Jugurtha 96 that while Marius was besieging a hill stronghold on the Mauretanian border Sulla arrived with a large body of cavalry raised from Latins and allies.  This is in addition to the cavalry Marius has in Jugurthan War 91, with which he captures Capsa in a coup de main.  It might be possible to infer from this that Marius already had an allocation of legionary cavalry and Sulla's contingent was a bonus, and draw a thin and shaky thread across to 48 BC and suggest that Pompey's legions each had a cavalry contingent assigned and the extraneous contingents named by Caesar formed a similar 'bonus cavalry group'.  This in turn would suggest that the reason Caesar does not detail c.3,400 of the c.7,000 Pompeian cavalry at Pharsalus is because they were legionary cavalry, or at least cavalry attached to legions at the rate of 300 per legion.  Scipio in Civil War III.31.3 raises 'legions and cavalry' in Syria, but I do not recall Syrians (as opposed to Commagenians) featuring among the named Pompeian cavalry contingents, which might be an indication that at least some of Pompey's cavalry were integral legion contingents in the old style.

Anyway, the thought is there for those who may wish to make use of it.

[Jim Webster]

I cannot see why Caesar would miss mentioning legionary cavalry. After all, given that he didn't have any, it's another example of how his understrength legions managed against the odds.
Also as he was supposed to be sparing Italians but not allies, you'd have thought he'd have mentioned how he managed to spare them

I don't say there wasn't 'legionary' cavalry on the Pompeian side, it's just that using them to fill a 'gap' doesn't provide me with convincing evidence for their existence.

Firstly where is Pompey going to get enough wealthy Italians to fill their ranks, and if he used allies as he did with the light infantry, they'd have been mentioned along with the infantry

Jim

[Duncan Head]

Firstly where is Pompey going to get enough wealthy Italians to fill their ranks

We did discuss in the other thread - http://soa.org.uk/sm/index.php?topic=1729.0 - that the stabbing-in-the-faces anecdote might imply that some of the cavalry were Roman aristocrats. It doesn't give us any idea of numbers, but they might make up some of  the shortfall.

[Patrick Waterson]

While the cavalry being raised in Syria as per Civil War III.31.3 are unlikely to consist of Roman aristocrats, they are by no means the majority and Pompey was followed to Greece by quite a swarm of senatorial types.  One might expect the latter's extended families to bring along numerous equites of their acquaintance.

I cannot see why Caesar would miss mentioning legionary cavalry.

Perhaps because they would have been taken for granted by his contemporary readership/audience, whereas Pompey's mounted ex-slaves, Thracian cavalry and Commagenian horse archers would not?  It may be that a contemporary Roman would see it as: oh, he had the opposing legionary cavalry to cope with, but in addition there are all these barbarians.

Besides, it might just not have suited Caesar's image to state: oh, by the way, lots of the best and brightest of the Roman nobility were lined up against me, serving with Pompey's legionary cavalry.  I encouraged my legionaries to give them gruesome facial mutilations just to show what I thought of these scions of Rome.  Some things are best left unsaid for a contemporary audience.

[Jim Webster]

What I meant about Caesar not mentioning Legionary cavalry is that if they were normal, why didn't he mention the fact that he didn't have any?
Even if only on the lines of, 'In my army well born young men are happy to fight in the ranks with the rest of the Romans, rather than pratting about on horses so they can run away more easily with the orientals'

Jim