How many legions and equivalents at Zama?

mariusj

Ad Honorem
Aug 2015
2,057
Los Angeles
The topic of numbers at Cannae is not one that I have thought too deeply about, certainly not enough to have a strong opinion, but to show the other side of the debate, I'll quote Lazenby 1978, Hannibal's War, 75-76:

'But the most important question concerns the number of legions Varro and Aemilius Paullus eventually had at Cannae. Polybius states quite unequivocally (3.107.9) that it was decided "to maintain the struggle with eight legions, a thing which had never happened among the Romans before, each of the legions having up to 5000 men, apart from the allies," and this, if true, means that it was decided to raise four new legions, each of 5000 men, and to bring the existing four under Servilius and Atilius up to the same strength. He also believed that an equal number of allied infantry was levied, and consistently with this says that the Romans had 80,000 infantry at Cannae (3.113.5). These figures have been doubted, because Livy (22.36.1-4), although he reports this tradition, also records a variant one - that only 10,000 fresh troops were raised - and it is argued that the smaller is to be preferred a priori, and that Hannibal's tactics at Cannae are unintelligible if he was really outnumbered by nearly 2:1 in infantry. But the a priori argument is not necessarily to be accepted - it is very difficult, for example, to accept the lowest of the three estimates Livy gives (29.25.1-4) for the army Scipio took to Africa in 204, and some scholars would accept the highest. But a more serious objection to accepting the tradition that only 10,000 fresh troops were raised for the Cannae campaign, is that this would have only given the Romans a slight numerical advantage, even if the four existing legions under Servilius and Atilius were strengthened to 5000 men, and that as many allied soldiers were levied as Roman. For even if we accept that all the 10,000 were citizen soldiers, that would still only have meant 30,000 citizen troops in all, with 30,000 allied infantry in addition. But Hannibal had 40,000 infantry (3.114.5), and some of the Roman infantry were bound to be left to guard the camp on any day of battle - Polybius indeed believed that 10,000 were left to guard the larger of the two camps, and Appian (Hannibalic War 4.26) mentions 5000 in the smaller, for what it is worth. Thus Varro and Paullus, we are being asked to believe, were left to face Hannibal's 40,000 infantry with possibly as few as 45,000 of their own, while their 6000 cavalry (3.113.5) were actually outnumbered by Hannibal's 10,000 (3.114.5). If this was the case, the Romans had certainly learnt nothing from the Trebbia, for there they had tried to fight Hannibal with a slight numerical superiority in infantry, and with fewer cavalry, and they had lost. Moreover, it might be argued that Hannibal's tactics, far from being unintelligible if he were really outnumbered by something like 2:1 in infantry, would be unintelligible if his infantry on the field was nearly as numerous as the enemy's.

Finally, it is perhaps significant that Livy's circumstantial account of the Roman losses at Cannae, and of those taken prisoner or who escaped, presupposes the higher number: in particular, if twenty-nine military tribunes were really killed (22.49.16), there must have been at least five legions present, since there were only six such officers to a legion. In other words, Livy's figures for the Romans killed, and for those who survived whether as prisoners or fugitives, support Polybius' figures for the size of the Roman army, and it cannot be too strongly stressed that Polybius is quite emphatic about his figures, though he obviously realised that they were unusually high.'
Hannibal also left troops to guard his own camp. Didn't the remaining legionaries attack Hannibal's camp as well and Hannibal had to relieve them after holding the field? So Hannibal wouldn't have as much troops.

Logically, if there were two camps for the Romans logic dictate that they must face an opposing camp of Hannibal, or otherwise what is the purpose of maintaining a camp with a legion in it?
 
Oct 2018
2,085
Sydney
Hannibal also left troops to guard his own camp. Didn't the remaining legionaries attack Hannibal's camp as well and Hannibal had to relieve them after holding the field? So Hannibal wouldn't have as much troops.

Logically, if there were two camps for the Romans logic dictate that they must face an opposing camp of Hannibal, or otherwise what is the purpose of maintaining a camp with a legion in it?
I agree that Hannibal would have had troops guarding the camp, but as for the thing about legionaries attacking his camp, I seem to recall that that happened at the Trebia.
 
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mariusj

Ad Honorem
Aug 2015
2,057
Los Angeles
I agree that Hannibal would have had troops guarding the camp, but as for the thing about legionaries attacking his camp, I seem to recall that that happened at the Trebia.
The Romans who were made prisoners were not in the battle for the following reason. Lucius had left a force of ten thousand foot in his own camp, in order that, if Hannibal, neglecting his camp, employed his whole army in the field, they might during the battle gain entrance there and capture all the enemy's baggage: if, on the other hand, Hannibal, guessing this danger, left a strong garrison in the camp, the force opposed to the Romans would be reduced in numbers. The circumstances of their capture were more or less as follows. Hannibal had left an adequate force to guard his camp, and when the battle opened, the Romans, as they had been ordered, delivered an assault on this force. At first they held out, but as they were beginning to be hard pressed, Hannibal, who was now victorious in every part of the field, came to their assistance, and routing the Romans shut them up in their camp. He killed two thousand of them and afterwards made all the rest prisoners. The Numidians also reduced the various strongholds throughout the country which had given shelter to the flying enemy and brought in the fugitives, consisting of about two thousand horse.

It was from Polybius.
 
Jan 2018
20
England
I`ve recently been looking at the numbers of troops that Scipio would have had at his disposal in 202, and so this thread caught my eye - actually it was Nick`s link on RAT that brought me here.
The ancient source estimates for Scipio`s army size at Zama are all based upon maximum paper strengths for 4-6 legions and so, the figures provided are the most liberal of estimates possible.
The issues are that for Zama, that no one seems to mention camp guards and few modern histrorians pay much attention at all to detachments made by Scipio in the 202 campaign.
Scipio would have needed to:-
1. Guard his operational base at Castra Cornelia where he had stored the booty from his campaigns in Africa to date.
2. Maintain pressure on Utica (Livy does mention 2,000 troops doing this)
3. Hold the position at Tunes in order to blockade Carthage, preventing its resupply and reinforcement by land.
4. In addition to these static duties, he had also detached a body of 6,000 troops to assist Massinissa.

So, at the start of manoeuvres in the late summer to the early autumn of 202, he could have had up to 2 legion`s-worth of troops elsewhere. That would have been problematic if he had only brought 4 legions with him from Sicily. This would leave him only 10,000 Roman and Italian troops to oppose Hannibal and only a few Numidians (initially without Massinissa). Scipio would have been out-numbered both in infantry and cavalry.

Although Polybius and Livy do not commit to the size of Scipio`s army, actually they both agree on the number of ships in Scipio`s invasion fleet. Later, Appian also thinks 400 transports (plus other supply vessels) were used and the army consited of 16,000 men.
When Appian tells us the army was 16,000 (the lower estimate mentioned in Livy), he was referring only to the heavy infantry in the legions and so the army (including its velites) was four legions strong, with around 20,800 men. This ratio of troops to transports seems to be correct if we note that it corresponds to the case of Ptolemy I Soter`s fleet sailing for Cyprus in 306 BC, which contained 200 transports, and carried at least 10,000 infantry. (Diodorus XX 49.1).
I tend to think that 19-20,000 men was the total Roman army strength in 202 BC. This was after some minor actions fought in 204-3 BC; the siege of Utica, the attacks on Hasdrubal`s and Syphax`s camps, the battle close to Cirta where Syphax was captured and the effects of disease in camps at around 2% per annum.
The most men Scipio would have had at Zama would have been around 15,000 infantry - three whole legions, or four legions at 66% of paper strength.
 
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Nov 2018
211
Wales
Use of Diodorus to provide relevance here is inspirational.

The first is on supplying an army. It has been proven that a field army cannot usually be larger than 50k , (Alexander the Great and the Logistics of the Macedonian Army), except in specific cases. Often, this means supply by sea or river (Diodorus 73.1 2).

Specific to this thread he (Diodorus 82.4) , states another invasion of Rhodes in which:
Demetrius, gathering all his forces in the harbour at Loryma, made his fleet ready for the attack on Rhodes. He had two hundred warships of all sizes and more than one hundred and seventy auxiliary vessels; on these were transported not quite forty thousand soldiers besides the cavalry and the pirates who were his allies. There was also an ample supply of ordnance of all sorts and a large provision of all the things necessary for a siege.
Warships have their own crews (especially rowers), that auxilliary ships may not, thus an army around 50k could have been taken by 400 transports, is not unlikely.

Back to numbers at Cannae. One of the few figures given is 12000 mercenaries fighting for Hannibal (Polybius 15.11), who fought the Hastati .
As the whole battle was a hand-to‑hand affair [the men using neither spears nor swords], the mercenaries at first prevailed by their courage and skill, wounding many of the Romans, but the latter still continued to advance, relying on their admirable order and on the superiority of their arms.
At no point are the Hastati stated to be outnumbered. In fact the implication is that the numbers are about equal.

From Polybius (6.19):
the strength of each legion is brought up to four thousand two hundred, or in times of exceptional danger to five thousand
The tribunes in Rome, after administering the oath, fix for each legion a day and place at which the men are to present themselves without arms and then dismiss them. When they come to the rendezvous, they choose the youngest and poorest to form the velites; the next to them are made hastati; those in the prime of life principes; and the oldest of all triarii, these being the names among the Romans of the four classes in each legion distinct in age and equipment. They divide them so that the senior men known as triarii number six hundred, the principes twelve hundred, the hastati twelve hundred, the rest, consisting of the youngest, being velites. If the legion consists of more than four thousand men, they divide accordingly, except as regards the triarii, the number of whom is always the same.
Facing 12000 mercenaries must be around 12000 Hastati, and therefore 10 legions. Outnumbered, but victorious Hastati would have been mentioned imho

That is my central argument, which no one has yet disproved using any reasonable source. It doesn't mean I'm right, just not yet proven wrong. Of course, I may be wrong about 10 legions, because according to Livy (29.25):
There is a wide difference among historians as to the number of men transported into Africa. In some I find ten thousand infantry and two hundred horse; in others, sixteen thousand infantry and sixteen hundred horse. In others, again, I find it stated that thirty-five thousand infantry and cavalry were put on board the fleet, making the number more than one half greater. Some have not added an account of the number; among whom, as the matter is doubtful, I should rather have myself ranked. Caelius, though he abstains from specifying the number, increases the impression of their multitude indefinitely. He says, that birds fell to the ground from the shout of the soldiers, and that so great a multitude went on board the fleet, that it seemed as if there was not a man left in Italy or Sicily.
In this case, we could have around 4 legions, 8 legions or dozens of them.
 
Jan 2018
20
England
Thanks, that`s another good example of the possible capacity of ships carrying troops in Scipio`s case.

Right, the 16,000 is four legions without light infantry (Livy also mentions 1,600 cavalry)
The 10,000 infantry is the Roman legions counted - but rounded down to the nearest thousand, but to a Roman contemporary, familiar with army organisation, this would in fact also make an army total of around 20,000 if 2 Italian allied legions were added.
The 35,000 you quote in Livy 29.25 is sometimes 32,000 in other translations. The 32,000 is, of course an exact doubling of 16,000 and an exaggerated figure

The cavalry figures seem to indicate that the 2,200 in Livy`s first example were the product of adding 1,600 cavalry + the Roman cavalry again (600)...
and so we find that 16,000 was the earlier source. This matches the 400 ships which all seem to agree on.
In Livy 29.25 we have two similar (early) estimates which are expressed in different ways and one later exaggerated one. Livy I think, would have leant towards the lower estimate, but Roman historians (like Valerius Antias for example) may have exaggerated Roman numbers to make Scipio`s army large seem large enough to defeat Hannibal`s in a large scale open battle.
I think we find the tendency to try and make the numbers, or the events in the great Battle of Zama make sense in so many histrorians` work.
The way the elephants were countered is but one example:
1. Originally we have the elephant lanes in Polybius
2. There were also heavy stakes ("two cubits long") in front of the Roman maniples in Appian.
3. Rather than channeling charging elephants down intervals between the maniples, Cassius Dio has the Roman infantry shout and cheer to frighten the elephants away.
4. Much later it was claimed that the elephants were not properly trained and so were easily frightened (I believe that Dodge was one of the earliest authors who suggested this).

The 12,000 mercenaries in Polybius are not just heavy troops. He lists "Balearic Islanders, and Moors" who would most likey be slingers and javelinmen.
There may quite probably have been only 10,000 spearmen/swordsmen in this line, but then I don`t think there was a large battle fought at Zama for the reason that Scipio`s army was just not large enough to fight Hannibal`s first two lines as described by Polybius, let alone mix it up with his 12,000+ veterans.
 
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Nov 2011
1,146
The Bluff
Use of Diodorus to provide relevance here is inspirational.
Loryma is a hop, skip and a jump to Rhodes (some 26km). Nothing supposes that Demetrios transported short of 40,000 men, and "ample supply of ordnance of all sorts and a large provision of all the things necessary for a siege" in the single trip. And, given his siege equipment, it is far more likely he did not given the short journey.

Facing 12000 mercenaries must be around 12000 Hastati, and therefore 10 legions. Outnumbered, but victorious Hastati would have been mentioned imho

That is my central argument, which no one has yet disproved using any reasonable source. It doesn't mean I'm right, just not yet proven wrong. Of course, I may be wrong...
If that is central to your agument, your argument falls as has been pointed out to you repeatedly and now also by Michael Collins (below). You continue to assert that slingers and javelin throwers fought Roman heavy infantry in close quarter, hand to hand combat. This is a military nonsense.

The 12,000 mercenaries in Polybius are not just heavy troops. He lists "Balearic Islanders, and Moors" who would most likey be slingers and javelinmen.
There may quite probably have been only 10,000 spearmen/swordsmen in this line...
 
Jan 2018
20
England
Just to amend my earlier post... that would be "four legions at 66% of paper strength" if a legion`s worth of vexillations (or detachments) had been made to perform camp and siege duties
 
Nov 2018
211
Wales
Thanks, that`s another good example of the possible capacity of ships carrying troops in Scipio`s case.

Right, the 16,000 is four legions without light infantry (Livy also mentions 1,600 cavalry)
The 10,000 infantry is the Roman legions counted - but rounded down to the nearest thousand, but to a Roman contemporary, familiar with army organisation, this would in fact also make an army total of around 20,000 if 2 Italian allied legions were added.
The 35,000 you quote in Livy 29.25 is sometimes 32,000 in other translations. The 32,000 is, of course an exact doubling of 16,000 and an exaggerated figure

The cavalry figures seem to indicate that the 2,200 in Livy`s first example were the product of adding 1,600 cavalry + the Roman cavalry again (600)...
and so we find that 16,000 was the earlier source. This matches the 400 ships which all seem to agree on.
In Livy 29.25 we have two similar (early) estimates which are expressed in different ways and one later exaggerated one. Livy I think, would have leant towards the lower estimate, but Roman historians (like Valerius Antias for example) may have exaggerated Roman numbers to make Scipio`s army large seem large enough to defeat Hannibal`s in a large scale open battle.
I think we find the tendency to try and make the numbers, or the events in the great Battle of Zama make sense in so many histrorians` work.
The way the elephants were countered is but one example:
1. Originally we have the elephant lanes in Polybius
2. There were also heavy stakes ("two cubits long") in front of the Roman maniples in Appian.
3. Rather than channeling charging elephants down intervals between the maniples, Cassius Dio has the Roman infantry shout and cheer to frighten the elephants away.
4. Much later it was claimed that the elephants were not properly trained and so were easily frightened (I believe that Dodge was one of the earliest authors who suggested this).

The 12,000 mercenaries in Polybius are not just heavy troops. He lists "Balearic Islanders, and Moors" who would most likey be slingers and javelinmen.
There may quite probably have been only 10,000 spearmen/swordsmen in this line, but then I don`t think there was a large battle fought at Zama for the reason that Scipio`s army was just not large enough to fight Hannibal`s first two lines as described by Polybius, let alone mix it up with his 12,000+ veterans.
Apologies for my tardiness. It's the kids last days at school before Christmas, but will reply tomorrow.