Size of Hannibal's Army Ebro-Po

Sep 2019
187
Vergina
How is Alexander defeating the great Indian armies such as that of Porus and completing sieges like that of the Mallian capital with just 30,000 men? The distance between Persepolis and northern India is about the same as the distance between Persepolis and Greece. Alexander had extensive time to prepare for the campaign in India. He wouldn't have advanced so deep into India with just 30,000 men in my opinion.
That 30,000 number is for Alexander exiting India, I imagine it was somewhat larger embarking on the campaign. I'm not sure we should judge the army's effectiveness by its size, Alexander had an elite veteran core that could basically overcome any obstacle within reason. Porus does not look to have very many men himself, Arrian says he numbered only 34,000. We also should remember that Alexander and his army did, in the end, turn back when it became unreasonable to continue.
 
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mariusj

Ad Honorem
Aug 2015
2,057
Los Angeles
The place they were "roaming" was Cannae where the "supply camp" was already taken over by the carthaginians.... Also you have ignored the fact that storing supplies for super armies of 80 000+ men is not practical, since such armies would rarely if ever be gathered in one place and the romans were unlikely to have such huge surpluses at hand to be stocked in not one but multiple (number unspecified by you) "supply camps".... ....

And yes you do have to explain how this super army of 80 000+ would have been supplied....
Gabriel's Hannibal

The Roman army marched along the coastal plain of Foggia with the sea on its left until it approached the Aufidus River and then turned south, keeping the river on its left and encamping on the western bank two miles from the sea.


Supplies could be accessed by the sea, and the Romans fetches water via the Aufidus river according to Livy. Pallus had a camp was built ahead of the main camp on the other side of Aufidus to cover the foragers and water carrier.
 

Tulius

Ad Honorem
May 2016
6,526
Portugal
Read this article. See also this article about settlement density, which is about the Near East but can be applied to Europe as well seeing how Europe had always had comparable degrees of settlement density as pointed out by Colin Renfrew. The specific high end estimate of 6 million comes from the high end population of Gaul, which has also been estimated at that by the time of Julius Caesar, which is less than two centuries later so there wasn't much change.
Thanks for the links to the articles.

So, I assume that using the methodology of those two articles, you made your own calculations for the Iberian Peninsula. Ok.

Edit: From Angus Madison's Contours of World Economy

View attachment 25229
Thanks.

These calculations are interesting, and are certainly an approach, I already saw similar numbers in this range, but with the sources that we have they must be seen as what they are, estimatives, and so need to be threaded with some care.

I also saw here estimatives for the Modern period, and although also estimatives, those have much more sources, since we have reports of the number of (fogos) houses that could be taxed, and from there we can directly infer by approximation the number of people.
 

Duke Valentino

Ad Honorem
Jul 2017
2,367
Australia
A lot can be and has been written about the numbers of Hannibal's army from Spain to Italy in the Academic world, and I shy away from attempting to bring a full critical analysis and discussion here. My general opinion here is that Polybius is a reliable source of info but also prone to human error, as we have seen from his account on Cannae. However, we must base our figures on some good grounding, and I don't see any reason to contradict Polybius' claim from the Lacinian tablet that Hannibal left about 20,000 garrison troops in Africa and 15,200 in Spain (3.3). Separate from these, he claims that Hannibal made off with 102,000 men, leading to a total of some 137,000 men. Following Polybius' account further, he left 11,000 behind under Hanno and released 11,000 Spaniards, eventually crossing the Pyrenees with 59,000 men. This would mean that Hannibal's subjection of the tribes north of the Ebro had caused him to lose 21,000 men in a short campaign - a total of losses far beyond the combined casualties of his major battles in the war. Delbruck believes that this is the key to understanding Polybius' role in recording the numbers, stating:

If under such circumstances a seasoned army is to sacrifice as a matter of course far more than half of its strength on a march of about two months' duration, then the marches of Caesar, which were carried out for the most part over the same routes as those of Hannibal, from Italy to Spain and from Spain to Italy, as well as the marches of Alexander in Asia, become completely inconceivable, and it also becomes incomprehensible that the strength of the Carthaginian army in the following campaigns in Italy was so well maintained.

Consequently, there is no other possibility but that the Lacinian tablet did not contain an accounting of the strength of the Carthaginian army as it marched out, that Polybius combined information from other sources with that of the Lacinian tablet and arrived at the huge march losses through the differences. In just the same way, of course, he also arrived at the exaggerated loss of 70,000 men by the Romans at Cannae. Consequently, we do not know how large Hannibal's army actually was when it crossed the Ebro.


Delbruck, Warfare in Antiquity, 357-8.

In other words, Delbruck posits that all these casualties Hannibal suffered marching to the Ebro was simply calculated by Polybius via subtracting the difference in the army sizes on the tablet. To corroborate this, Delbruck points to Poly. having done the same for the loss of 70,000 Roman at Cannae. Thus Delbruck comes to the important conclusion "Precisely for this reason we can assume that Hannibal listed on the Lacinian tablet only those troops that he left behind in Spain and Africa and those with which he arrived in Italy." (358) Now, for Hannibal's army upon the arrival of Italy, Poly. deriving from the tablet states 12,000 Africans, 8,000 Iberians, 6,000 cavalry. However, Hannibal's light infantry are missing. Polybius mentions 8,000 Balearics and peltasts for the battle of Trebia. Are we to simply believe these should be included in the figure of 20,000 infantry Hannibal had upon arrival in Italy? That would leave him with only 12,000 heavy infantry upon arrival in Italy, but this doesn't add up later on. As Delbruck correctly points out, only 9,000 or 10,000 of them could be present at Cannae by that point, though that makes no sense when factoring in the compositions of the army:

In that battle he mixed the Iberians in units among the Celts in the center, and with the Africans he made the envelopments on the right and the left, but it is impossible to see how either the 3,000 to 4,000 Iberians mixed among the 22,000 Celtic hoplites or the 5,000 to 6,000 Africans assigned to the two flanks could have accomplished the missions that were demanded of them and that they reportedly achieved.

Delbruck, Warfare in Antiquity, 361.

I can expand on this if anyone has any questions specifically, but I think that, in general, Delbruck provides the most logical deduction of how Polybius arrived at the numbers reported on the tablet. So, working backwards, if Hannibal arrived in Italy with 34,000 men (adding in the light infantry Poly. makes no mention of until Trebia), Hannibal might have started out with say 36,000 men (it's entirely ludicrous that Hannibal lost tens of thousands of men against hostile tribes in 2 months of marching). With about 20,000 left in Africa and 26,000 in Spain, altogether he had something not 137,000 strong, but rather about 82,000 strong. In other words, Hannibal planned to move on Italy with a strong core of something closer to 40,000 men, which retains logistical credibility for the time period, and amounts to about the maximum army size we generally see when looking at army corps from the period.

----

As for Cannae, I don't think there's any doubt now that the Romans did field 16 legions, though I don't like the way people misrepresent the battle as 50,000 vs 80,000. A good portion of that 80,000 would have been combatants who were made "non-combatants" by the simple fact that it was impossible to field them.
 

mariusj

Ad Honorem
Aug 2015
2,057
Los Angeles
A lot can be and has been written about the numbers of Hannibal's army from Spain to Italy in the Academic world, and I shy away from attempting to bring a full critical analysis and discussion here. My general opinion here is that Polybius is a reliable source of info but also prone to human error, as we have seen from his account on Cannae. However, we must base our figures on some good grounding, and I don't see any reason to contradict Polybius' claim from the Lacinian tablet that Hannibal left about 20,000 garrison troops in Africa and 15,200 in Spain (3.3). Separate from these, he claims that Hannibal made off with 102,000 men, leading to a total of some 137,000 men. Following Polybius' account further, he left 11,000 behind under Hanno and released 11,000 Spaniards, eventually crossing the Pyrenees with 59,000 men. This would mean that Hannibal's subjection of the tribes north of the Ebro had caused him to lose 21,000 men in a short campaign - a total of losses far beyond the combined casualties of his major battles in the war. Delbruck believes that this is the key to understanding Polybius' role in recording the numbers, stating:

If under such circumstances a seasoned army is to sacrifice as a matter of course far more than half of its strength on a march of about two months' duration, then the marches of Caesar, which were carried out for the most part over the same routes as those of Hannibal, from Italy to Spain and from Spain to Italy, as well as the marches of Alexander in Asia, become completely inconceivable, and it also becomes incomprehensible that the strength of the Carthaginian army in the following campaigns in Italy was so well maintained.

Consequently, there is no other possibility but that the Lacinian tablet did not contain an accounting of the strength of the Carthaginian army as it marched out, that Polybius combined information from other sources with that of the Lacinian tablet and arrived at the huge march losses through the differences. In just the same way, of course, he also arrived at the exaggerated loss of 70,000 men by the Romans at Cannae. Consequently, we do not know how large Hannibal's army actually was when it crossed the Ebro.


Delbruck, Warfare in Antiquity, 357-8.

In other words, Delbruck posits that all these casualties Hannibal suffered marching to the Ebro was simply calculated by Polybius via subtracting the difference in the army sizes on the tablet. To corroborate this, Delbruck points to Poly. having done the same for the loss of 70,000 Roman at Cannae. Thus Delbruck comes to the important conclusion "Precisely for this reason we can assume that Hannibal listed on the Lacinian tablet only those troops that he left behind in Spain and Africa and those with which he arrived in Italy." (358) Now, for Hannibal's army upon the arrival of Italy, Poly. deriving from the tablet states 12,000 Africans, 8,000 Iberians, 6,000 cavalry. However, Hannibal's light infantry are missing. Polybius mentions 8,000 Balearics and peltasts for the battle of Trebia. Are we to simply believe these should be included in the figure of 20,000 infantry Hannibal had upon arrival in Italy? That would leave him with only 12,000 heavy infantry upon arrival in Italy, but this doesn't add up later on. As Delbruck correctly points out, only 9,000 or 10,000 of them could be present at Cannae by that point, though that makes no sense when factoring in the compositions of the army:

In that battle he mixed the Iberians in units among the Celts in the center, and with the Africans he made the envelopments on the right and the left, but it is impossible to see how either the 3,000 to 4,000 Iberians mixed among the 22,000 Celtic hoplites or the 5,000 to 6,000 Africans assigned to the two flanks could have accomplished the missions that were demanded of them and that they reportedly achieved.

Delbruck, Warfare in Antiquity, 361.

I can expand on this if anyone has any questions specifically, but I think that, in general, Delbruck provides the most logical deduction of how Polybius arrived at the numbers reported on the tablet. So, working backwards, if Hannibal arrived in Italy with 34,000 men (adding in the light infantry Poly. makes no mention of until Trebia), Hannibal might have started out with say 36,000 men (it's entirely ludicrous that Hannibal lost tens of thousands of men against hostile tribes in 2 months of marching). With about 20,000 left in Africa and 26,000 in Spain, altogether he had something not 137,000 strong, but rather about 82,000 strong. In other words, Hannibal planned to move on Italy with a strong core of something closer to 40,000 men, which retains logistical credibility for the time period, and amounts to about the maximum army size we generally see when looking at army corps from the period.

----

As for Cannae, I don't think there's any doubt now that the Romans did field 16 legions, though I don't like the way people misrepresent the battle as 50,000 vs 80,000. A good portion of that 80,000 would have been combatants who were made "non-combatants" by the simple fact that it was impossible to field them.
As discussed before, Cannae has 2 separate battles, Rom left behind 2 legions to guard their camp, forcing Hannibal too to leave behind a force to protect his own camp. So the 80,000 starts off with only 70,000, 50k infantry and 20k skirmishers.

And I don't think it is impossible to field 50,000 heavy infantry in a mile. Let's say it's 2 ft of space each soldier need in a pack formation, that is 5280 ft/2 ft per man = 2640 men, spread out for 50k men would be 19 ranks. A typical legion has 6 ranks of hastatii, 6 ranks of principes, and 3 ranks of triaii.

I don't think it is inconceivable at all.
 
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Oct 2015
1,009
Virginia
Nonsense. There are any number of literary and practical reasons to doubt 16 legions and Alae at Cannae. It is simply Polybius vs Livy, Wallbank and Toynbee vs Brunt, DeSanctis and Hallward. I don't see anything convincing or new in Lazenby or Goldsworthy et al. It's simply a matter of what you want to accept.
26,000 men arriving in Italy with Hannibal is the most accurate number you'll ever see in any primary source ever. Attested not only by Polybius, but by the monument erected by Hannibal himself on the Lacinian Promontory.
 

mariusj

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Aug 2015
2,057
Los Angeles
Nonsense. There are any number of literary and practical reasons to doubt 16 legions and Alae at Cannae. It is simply Polybius vs Livy, Wallbank and Toynbee vs Brunt, DeSanctis and Hallward. I don't see anything convincing or new in Lazenby or Goldsworthy et al. It's simply a matter of what you want to accept.
26,000 men arriving in Italy with Hannibal is the most accurate number you'll ever see in any primary source ever. Attested not only by Polybius, but by the monument erected by Hannibal himself on the Lacinian Promontory.
I look forward for you to enumerate these 'any numbers of literary and practical reason' rather than stating that there exists such numbers of reasons.
 
Oct 2015
1,009
Virginia
See #9 and #14 above.
Livy xxii.36 which cites several alternate (but unfortunately unnamed) sources that contradict Polybius iii.107.
Hallward (Cambridge Ancient History (1954) vol viii), De Sanctis (Storia de Romani) and Cantalupi who question whether Polybius or his source misinterpreted the term "stratopedon" in their source.
P A Brunt (Roman Manpower) who says: "the mortality in the disaster, like the number of troops engaged is grossly exaggerated."
The fact that Roman literature was apt to exaggerate disasters in order to magnify the glory of the final victory. In this case the victory of Polybius' patrons the Cornelii Scipiones.
The size of the Roman army is calculated backwards by Polybius based on questionable casualty reports, just as his exaggerated estimates of Hannibal's numbers in Spain.
The fact that NO Roman army is attested (prior to the Social War) larger than two combined consular armies (eg 4 legions plus 4 Alae of Latin and Italian allies).
Logistical and command and control issues under the conditions of the time make a unified army of 87,000 unlikely.
The Roman senate was not likely to see mere numbers as an unqualified asset in opposing Hannibal. At Trebbia and Trasimene the Roman commanders had placed themselves in unfavorable tactical positions, the senate had enough military experience to see that the defeats were not due to the lack of fighting ability of the troops, and there was no reason to pile legion upon legion, presenting the Roman commander with a unique and difficult command, control and logistical problem.
Finally (as i've said before) it is difficult to understand how Hannibal could annihilate an army twice the size of his own under any conceivable tactical circumstances.

I don't say that Polybius' numbers are impossible or objectionable in some way, only that I object somewhat to saying "there is no reason to doubt", because there is. Since there is no way to prove the issue one way or the other, folks are free to think what they like.
 
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mariusj

Ad Honorem
Aug 2015
2,057
Los Angeles
See #9 and #14 above.
Livy xxii.36 which cites several alternate (but unfortunately unnamed) sources that contradict Polybius iii.107.
Livy xxii.36

The armies also were augmented. But how large were the additions of infantry and cavalry I should hardly venture to declare with any certainty —so greatly do historians differ in regard to the numbers and kinds of troops. Some say that ten thousand new soldiers were enlisted as replacements; others that four new legions were enrolled, so that they took the field with eight. Some assert that the legions were also increased in the numbers of their infantry and cavalry, and that each received an additional thousand foot and a hundred horse, bringing up the total of every one to five thousand foot and three hundred horse; and that double the number of horse and an equal number of foot were furnished by the allies. One thing is not disputed —that they proceeded with more energy and enthusiasm than in former years, because the dictator had given them ground for hoping that they would be able to defeat the enemy.



So in the case of Livy, the difference was between 4 legions or 10,000 men. That was the main contention between 4,200 * 4 vs 10,000, the difference is 6800.

Then if we were to consider that the allies were to match these numbers the difference would be a total of 13600 on that count.

However, it then mentioned that each legion received an additional thousand foot and a hundred horses, on the assumption that the Romans carried out their struggle with 6 legions (rather than 8) that would means there were 12,,000 foot, changing that difference of 13600 to the difference of 1600.

That is to say Livy's difference would be
6 Roman legions * (4200/legion + 1100) + 6 Allies ( 4200/legion + 1400) = 65400

Polybius asserted
8 legions of Romans at 5000 + 8 legions of allies at 5000 = 80000

Without considering over strengthen legions we would have
8 legions of Romans at 4200 and 8 legions of allies at 4200 = 67200

The dispute then isn't whether or not there are possible 8 legions taking the field, it's whether or not 8 strengthened legions took the field.

Hallward (Cambridge Ancient History (1954) vol viii), De Sanctis (Storia de Romani) and Cantalupi who question whether Polybius or his source misinterpreted the term "stratopedon" in their source.
P A Brunt (Roman Manpower) who says: "the mortality in the disaster, like the number of troops engaged is grossly exaggerated."
Brunt's argument was essential, it's impossible to win a battle 2:1 therefore we should take the Livy's view of strengthened legions rather than Polybius' 8 legions or 8 strengthened legions.

Brunt
"Livy had read that Roman army comprised either 4 legions strengthened by 10,000 recruits (of whom at least half would have been allies) or 8 legions, each 5500 strong, with proportionately large allied contingents, making an army of 8700. Polybius adopts the second view, and gives a total strength of 80000 foot plus (it appears) 6000 horses. The first account is to be preferred, not only for the reasons De Sanctis gives but because the success of Hannibal's tactics is unintelligible if the Roman forces outnumbered his own by two to one. Livy's details on casualties presuppose the large total; the rival estimate which must have been given by the authority for the smaller sie of the army is lost.'

Now I find this position questionable. For one, it presumes that a victory of that magnitude was impossible. Why?

Second, Hannibal's forces did not fight the entire Roman army, as 2 legions were detached by Rome which was attacking Hannibal's camp, and Hannibal left behind a smaller force (we don't know the actual number) that was resisting the Romans. Hannibal's infantry that fought against the Roman infantry was not a 2:1 ratio.

I don't have access to De Sactis or Cantaplupi, so you would have to quote these people, however, for Cambridge Ancient History vol 8, it wasn't written by Hallward, but rather John Briscoe

The six-month term of the dictator elapsed before the end of the consular year, and the armies of Fabius and Minucius reverted to the consuls M. Servilius Geminus and C. Atilius Regulus (who had been elected to replace the dead Flaminius). For 216 the new consuls were L. Aemilius Paullus and C. Terentius Varro. Polybius reports that it was decided to give the consuls a force of eight legions of 5,000 men each, which, with the same number of allied troops, meant a total force of 80,000. There is no need to doubt these figures and it is the size of the Roman army that made the third Roman defeat particularly devastating. Hannibal occupied Cannae, by the River Aufidus, an important supply base for the Romans in Apulia.


So ultimately Brunt rests his argument on 1) it's impossible to win a really hard fight and 2) what De Sanctis said.

So please give us what De Sanctis said.

The fact that Roman literature was apt to exaggerate disasters in order to magnify the glory of the final victory. In this case the victory of Polybius' patrons the Cornelii Scipiones
This is pure speculation.

The size of the Roman army is calculated backwards by Polybius based on questionable casualty reports, just as his estimates of Hannibal's numbers in Spain.
Do you have a source on how Polybius arrived at his number through backward calculations?

The fact that NO Roman army is attested (prior to the Social War) larger than two combined consular armies (eg 4 legions plus 4 Alae of Latin and Italian allies)
Isn't that a no True Scotsmen argument?


Logistical and command and control issues under the conditions of the time make a force of 87,000 unlikely.
This army marched by the sea and was near a river. It could be perfectly be supplied from the coast.

The Roman senate was not likely to see mere numbers as an unqualified asset in opposing Hannibal. At Trebbia and Trasimene the Roman commanders had placed themselves in unfavorable tactical positions, the senate had enough military experience to see that the defeats were not due to the lack of fighting ability of the troops, and there was no reason to pile legion upon legion, presenting the Roman commander with a difficult command control and logistical problem.
The Roman senate took over the direction of the war after Cannae. Do you have a source that the consuls prior to Cannae was NOT in control of their war?


Finally (as i've said before) it is difficult to understand how Hannibal could annihilate an army twice the size of his own under any concievable tactical circilumstancr
How many actual military commanders says this?