Could the Persian Empire logistically support an army several million strong?

[Erpingham]

It really depends upon how kind the Achaemenids were to their animals.

Not really.  It depends on whether they need them to last more than a couple of weeks.  If the Persian army is even moderately competent, it will load its animals according to the job to be done - long range travel in rough conditions.

What I dislike is the 'cultural racism' approach which seems to take for granted that any tale told in classical Greek sources must be the inventive product of an inferior mind.

Of which there is no evidence whatsoever here.  Herodotus may live in a world in which faith, myth and reality were intertwined whereas we do not.  This is evidence of a different world view, rather than an inferiority of mind. 

[Justin Swanton]

3) Curious geometric rather than arithmetic increase in animals.
1 day's supply = 5,750 animals
10 days' supply = 4,710,000 animals (should be 57,500)
If the army is eating 5,750 animal loads' worth on day 1, it will eat the same on each of days 2-10.  Ergo, the number of animals needed to carry supplies for ten days = 10x the number of animals needed to carry supplies for one day.  Young's arithmetic is wildly out.

It's not quite that simple - as Engels points out with detailed calculations, IIRC - because all the extra pack animals have to eat from the supplies they carry, as well. An army with x men, y horses, and z pack animals will need a lot less than an army with x men, y horses, and 10z pack-animals. (Unless they can graze, and of course the more animals you have, the harder it is to find enough grazing.) Doesn't Engels claim that no army can carry more than about eight days' worth of provisions, because beyond that the extra pack animals are just eating their own loads? There are ways round the problem (like redistributing loads and then eating the spare animals, feeding them to Thracian lions, or even just sending them back) but you can't just use an arithmetic progression.

A valid point, and an illuminating one in view of the classical period habit of carrying about one week's worth of provisions in the baggage train, although once one has allowed for the additional animals to carry fodder for the other animals the increase is still more arithmetic than geometric.  I calculated (roughly) 135,000 animals to feed the army for a week rising to around 400,000 if they have to carry fodder to feed themselves.  This is still a whole order of magnitude lower than Young's 4 million.

Has anyone given thought to the Texan cattle drives? Herds of up to 10 000 cattle could travel over 500 miles at a rate of 10 - 12 miles a day through dry country and not have anything to each or drink except what they could find en route - and they had to be in good condition at the end.

The Achaemenid army will have animals several times more numerous than the largest drive, but theirs are smaller beasts, traveling through countryside with more grass than in Texas and are not expected to last.

[Duncan Head]

The Achaemenid army ... animals ... are not expected to last.

That may be one of the key issues, not just for this expedition but for ancient logistics in general. Maurice, Engels and the like calculate consumption based on what's needed to keep pack animals in a usable condition; the picture is a bit different if they are expendable.

But are they expendable? If you're on a march for a limited time and you expect to be able to get new mules (camels, whatever) the next time you need them, yes. If you're still going to need the animals to shuttle food from shipborne deliveries to the army in six months' time, and your army's so big that Greece (which doesn't breed camels, or apparently all that many mules) can't supply enough replacement beasts, then your pack animals surely do need to last.

[Dangun]

What I dislike is the 'cultural racism' approach which seems to take for granted that any tale told in classical Greek sources must be the inventive product of an inferior mind.

Is that a thing?

Anyway, Herodotus' mind may have been capable of a lot. Maybe even more capable than most. But there was just a lot less information and understanding to feed him with.
Its not his fault, but his understanding of many things would have been objectively primitive.

At this point in the thread I will channel my inner Douglas Adams, and call it quits with the dolphins.

It's not quite that simple - as Engels points out with detailed calculations, IIRC - because all the extra pack animals have to eat from the supplies they carry, as well.... Doesn't Engels claim that no army can carry more than about eight days' worth of provisions, because beyond that the extra pack animals are just eating their own loads?

Yes, in a nice little book, he said exactly that. (an edit: its page 20 he says 7 days with abundant water <3 if the water has to be carried.)

[Justin Swanton]

The Achaemenid army ... animals ... are not expected to last.

That may be one of the key issues, not just for this expedition but for ancient logistics in general. Maurice, Engels and the like calculate consumption based on what's needed to keep pack animals in a usable condition; the picture is a bit different if they are expendable.

But are they expendable? If you're on a march for a limited time and you expect to be able to get new mules (camels, whatever) the next time you need them, yes. If you're still going to need the animals to shuttle food from shipborne deliveries to the army in six months' time, and your army's so big that Greece (which doesn't breed camels, or apparently all that many mules) can't supply enough replacement beasts, then your pack animals surely do need to last.

Fine, so we suppose the Persians needed to keep most of their pack animals alive. They also needed to travel 20km a day at least when moving inland so as to reach the next sea-stop within 5 days where everyone can rest for a day or two. Whilst traveling let's assume the pack animals need to live entirely off the land. Texan herds, which were kept bunched together so as not to lose any of the cattle, managed it. What stops a Persian baggage train from managing it? The hypothesis supposes that the baggage train is considerably wider but no longer than the train of a conventional army - which also had to live off the land.

[Erpingham]

Has anyone given thought to the Texan cattle drives? Herds of up to 10 000 cattle could travel over 500 miles at a rate of 10 - 12 miles a day through dry country and not have anything to each or drink except what they could find en route - and they had to be in good condition at the end.

With respect, a cattle drive and an army on the march are not the same thing. There is virtually no individual care of the animals, no animals assigned to individuals as mounts, no animals working.   

I don't understand why anyone would think you just turned all the tens of thousands of animals out to graze at night and they would find the food they need. You have to care for them.  It's not a soft-hearted welfare thing - you have these animals either as transport or as weapons.  They need to be maintained to function effectively. 

[Justin Swanton]

Has anyone given thought to the Texan cattle drives? Herds of up to 10 000 cattle could travel over 500 miles at a rate of 10 - 12 miles a day through dry country and not have anything to each or drink except what they could find en route - and they had to be in good condition at the end.

With respect, a cattle drive and an army on the march are not the same thing. There is virtually no individual care of the animals, no animals assigned to individuals as mounts, no animals working.   

I don't understand why anyone would think you just turned all the tens of thousands of animals out to graze at night and they would find the food they need. You have to care for them.  It's not a soft-hearted welfare thing - you have these animals either as transport or as weapons.  They need to be maintained to function effectively.

Then you maintain them. Once the army reaches camp you unload the animals and take them to grazing ground or let them graze in situ. You then fetch them water or take them to water. An average hiker with backpack can manage 3km/h. That means 7 hours to cover 20km. Add faff factor and the journey takes 9 hours. That leaves several daylight hours to give the animals what they need.

I suspect foraging for animals became an issue only at stops of several days, which were all at the coast where fodder could be supplied directly from the ships.

[Flaminpig0]

From wikipedia Mule :

The median weight range for a mule is between about 370 and 460 kg (820 and 1,000 lb). While a few mules can carry live weight up to 160 kg (353 lb), the superiority of the mule becomes apparent in their additional endurance.

In general, a mule can be packed with dead weight of up to 20% of its body weight, or approximately 90 kg (198 lb).[6] Although it depends on the individual animal, it has been reported that mules trained by the Army of Pakistan can carry up to 72 kilograms (159 lb) and walk 26 kilometres (16.2 mi) without resting. The average equine in general can carry up to approximately 30% of its body weight in live weight, such as a rider.

From wikipedia pack animal

Loads for equids are disputed. The US Army specifies a maximum of 20 percent of body weight for mules walking up to 20 miles a day in mountains, giving a load of up to about 150 kg. However an 1867 text mentioned a load of up to 800 pounds (about 360 kg). In India, the prevention of cruelty rules (1965) limit mules to 200 kg and ponies to 70 kg.


Of course, we could use the idea that things were different in the past and ancient mules were super beasts capable of carrying vastly more or they were gigantically big, so 20% of their body weight was more but I'd suggest we aim at mule loads 72-150 kg for long range, difficult terrain work.  So Young is closer than Patrick here.

It really depends upon how kind the Achaemenids were to their animals.  Spanish in the Napoleonic Wars, for example, appear always to have loaded their mules to something like the 500 lbs mark.  US Army practice varied (as per the Wikipedia pack animals article) and Near Eastern societies on the whole are not noted for their concern for animal welfare.  So the average Achamenid mule load could be 250lbs, 500 lbs or anywhere in between (I am assuming that unlike the US Army they had not bred anything capable of standing up under 800 lbs).  Given that their masters would aim to carry the most material upon the fewest animals, I would go for around 500 lbs, noting that the load will get lighter every day so it is not quite as bad for the animals as it looks.

How does that sound?

Like something out of one of those American TV shows on minor channels that everyone watches for a laugh?

Actually I find Justin's suggestion quite reasonable.  We get unlikelier things happening in this day and age, and something noteworthy must have happened to Arion for such a tale (which is well within the known general behaviour patterns of dolphins) to be recorded.  What I dislike is the 'cultural racism' approach which seems to take for granted that any tale told in classical Greek sources must be the inventive product of an inferior mind.

You aren't seriously suggesting that questioning Herodotus is racist?

[Erpingham]

It's not quite that simple - as Engels points out with detailed calculations, IIRC - because all the extra pack animals have to eat from the supplies they carry, as well.... Doesn't Engels claim that no army can carry more than about eight days' worth of provisions, because beyond that the extra pack animals are just eating their own loads?

Yes, in a nice little book, he said exactly that.

It's a fairly straightforward calculation using figures from the internet.  A pack equid can carry 20% of its bodyweight for sustained periods.  It eats 2.5% of its body weight a day.  It therefore eats the equivalent of its load in eight days.  Give or take.  Mules are anecdotally more fuel efficient and you might get away with 2.0% body weight a day.  Rather than arguing the specifics (when none of us are mule wranglers), we should recognise Engels caution that, if using mules, you shouldn't be expecting a long gap between replenishment stops.

[Justin Swanton]

What I dislike is the 'cultural racism' approach which seems to take for granted that any tale told in classical Greek sources must be the inventive product of an inferior mind.

Of which there is no evidence whatsoever here.  Herodotus may live in a world in which faith, myth and reality were intertwined whereas we do not.  This is evidence of a different world view, rather than an inferiority of mind.

If recounting a man being saved by dolphins is the gauge of a mindset that mixes faith, myth and reality, then we live in a world that has a far greater proportion of faith and myth than in Herodotus' time since he reported only one dolphin incident whereas modern news outlets report dozens. 

[Erpingham]

I suspect foraging for animals became an issue only at stops of several days,

No, the cavalry would be worrying about fodder every day.  Probably every day they would be short and they would be concerned on the long term effect on the horses. And this would be with a realistic (i.e. comparable to other periods in military history) army.

If recounting a man being saved by dolphins is the gauge of a mindset that mixes faith, myth and reality, then we live in a world that has a far greater proportion of faith and myth than in Herodotus' time since he reported only one dolphin incident whereas modern news outlets report dozens. 

Thank goodness Herodutus didn't have access to social media

[Justin Swanton]

I suspect foraging for animals became an issue only at stops of several days,

No, the cavalry would be worrying about fodder every day.  Probably every day they would be short and they would be concerned on the long term effect on the horses. And this would be with a realistic (i.e. comparable to other periods in military history) army.

If recounting a man being saved by dolphins is the gauge of a mindset that mixes faith, myth and reality, then we live in a world that has a far greater proportion of faith and myth than in Herodotus' time since he reported only one dolphin incident whereas modern news outlets report dozens. 

Thank goodness Herodutus didn't have access to social media

[Justin Swanton]

Returning to Maurice for a bit, here are the stats for Camp Gordon, a WW1 US army training camp built in Georgia. It occupied an area of 2400 acres and could hold 47 000 troops. It had 1600 buildings and was spread out with plenty of space between the buildings as the photos show. Its 2400 acres = 971 hectares translates to 48 men per hectare.

Camp Hancock in Georgia occupied 1777 acres and could hold 50 000 men. it's a little more compact than Camp Gordon but still spread out, with 70 men per hectare.

So even by luxurious US training camp standards, Maurice is well off the mark.

[Erpingham]

I suspect that you are using a different approach to maurice.  He is thinking in terms of the sorts of concentration areas armies need to work from a fixed supply point and maintain military efficiency, not just how many men can be crammed in a space.  Doesn't mean he isn't on the generous side but lets try and get where he is coming from.  Poor chap, if he's been writing BC, we'd not bat an eyelid at his numbers .

AS an alternative comparator, what if we look at the Persian camp as more like a refugee camp - a few functional areas like hospitals, storage, assembly spaces and some closely arranged tents? If we take UNHCR guidelines

The average camp size is recommended by UNHCR to be 45 sqm per person of accessible camp area.    Sleeping accommodations are frequently tents, prefabricated huts, or dwellings constructed of locally available materials. UNHCR recommends a minimum of 3.5 sqm of covered living area per person. There should be at least 2m between shelters. 

The UNHCR allow 15sq m garden space per person, so actual camp density would be at 30 sq m per person.  In real lfe, they can be denser but lets stick to the guidance.  Of course, UNHCR camps tend to be settled with some infrastructure, so may well be more sophisticated than a daily camp.  But then again, they don't have thousands of cavalry and baggage animals. 

[Prufrock]

Pompey's troops at Dyrrachium had about the same area per man as in Maurice's example, given a 12km by 2.5km area as suggested by the Livius map and 45,000 men, so doesn't seem excessive if intending to stay for some time and there are a lot of animals as well. Another thing, as Anthony suggests, Maurice is using the British for comparison purposes, not as a model. He puts the Persian host into an area 3 miles by 7 before Thermopylae for instance, which is far more densely packed than the British.

Regarding the Scamander (Mendere) note that Maurice measures the Mendere at 20 feet side and 6 inches deep (see his notes) and that he treats what he calls the Homeric Scamander, fed by pools, as a separate watercourse (narrow, good water). Between them he thinks they would struggle to consistently deliver 400,000 usable gallons a day for a period of days.

I agree though that his numbers seem to be confusing here when compared to Justin's climate change paper - but that is not thoroughly consistent either, so it's a bit of a head-scratcher. It would be helpful to know what the army recon. formula he was using might have been. I've had a search but haven't had any luck turning anything up.