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

[Erpingham]

Assume an army of 3,5 million men split evenly between 3 avenues each 200 yards wide, with each man occupying a space of 2 x 2 yards, and you get 3 columns each 23.33 km or 15 miles long.

Without animals or baggage?

There isn't a great deal of point continuing because I suspect neither of us has the essential knowledge to either support or refute the theory.  For example, what was the terrain like in Thrace/Northern Greece?  Flat & open or wooded and hilly?  Is it easy to find three campsites for 1 million people, animals and baggage with sufficient water every 10-15 miles in easy distance of beaches to allow the delivery of 3,500 tons of food and however many tons of fodder (about 10kg per horse)? 

[Justin Swanton]

Google Earth is your friend. I did a virtual tour from the Dardanelles along the coast of Thrace and Macedonia as far as Kamena Vourla in Greece. It's only there that the first serious chokepoint appears, with mountains too high and steep to walk over. Along the Thracian and Macedonian coastline it's largely a breeze, with perhaps three chokepoints where the army would need to split and pass through several gaps in the hills. But nowhere was the traversable terrain less than 300m wide IMHO. I also checked the Drakensberg mountains as a reference where I've hiked. I honestly can't see the problem of a large army travelling in columns several hundred yards wide along the Aegean coastline with a couple of forays inland. You would need the clear the path of trees and undergrowth though (or even just undergrowth).

[Erpingham]

In the search for novelty, have we discussed this dissertation?  Even if you don't agree with the author's conclusions, he does provide some interesting information.

[Patrick Waterson]

If it can be proven that the entire army had to march along a single track or narrow road then we can automatically rule out several million men right away (the column would be ridiculously long). But if it marches along several wide, roughly-cleared avenues then poo is not a primary consideration.

Patrick's theory assumes that the whole army is next to the coast on a daily basis.  Doesn't this preclude "numerous roughly cleared avenues"?  Also, how long would each of the sub-columns be?  There is a paper on 17th century armies which concludes that an army of 60,000 men and its baggage would stretch 198km in single file.  I think it would need to be something like 15 wide for the  front to be reaching the new camp as the back left the old one.  You are talking of an army 60 times this size.  Ok, not entirely compatable - the persians are carrying much less food with them because they are resupplying daily - but it does provide a sense of proportion.

They would probably march about 100 men wide, hence needing a 300-600 yard front.  Herodotus mentions that the Thracians out of awe refrained from farming the land Xerxes' army had used, which suggests it was quite a wide strip.  One would not bother refraining from farming a swathe a mere 30 yards wide or so; well, one could, but it would just not be impressive enough to evoke a historic sense of awe.

We need to introduce another consideration, namely the army's own supply train and how much capacity it contained.  Following Hannibal's camapgins in 217-216 BC in Polybius indicates that he resupplied his baggage train abotu once a week; this gives us a rule of thumb that a baggage train would carry about a week's supplies and that therefore Xerxes' army could go about a week without resupply.  Looking at his advance to Thermopylae, he takes a detour inland through Macedon, and emerges on the coast near Thermopylae: duration, about a week, including a three-day stop to cut a way through a forest.  So a one week capacity for the baggage train may be about right.

The question of fodder is one which Anthony is right to raise: would there be sufficient in situ if the army kept moving, or if peoples along the route could be ordered to cut and stockpile it, or would it have to be fetched over from Asia?  Jim might be able to help here with the keeping qualities of fodder and the challenge of moving it around.  I am maybe a bit pessimistic and think the bring-in requirement would at least double the amount of shipping involved, and it is probably time to look at the capacity of the necesary shipping pipeline.

A shipping pipeline's capacity depends upon load carried over distance.  Concerning the aforementioned grain-carriers, if we have sixty 50-tonners unloading on any given day we also have, or should have, sixty loading at the other end of the terminus.  Crossing the Aegean would take how long?  If three days, then we need a pipeline with five days' capacity, i.e. 5x60 = 300 ships.  Double that, no, triple it to account for possible fodder required over and above locval availability and we need 900 ships to supply the army.

Xerxes had 3,000.

Anthony also raises the question of diet.  Yes, two pounds of bread per day is not great for variety or overall nutrition, but this is a basic ration for a limited period (one campaign season) and if we add in the meat available from foundered baggage animals and from local hospitality in northern Greece then perhaps the men are not doing too badly.  In any event it is not forever: at the end of the campaign they would be disbanded and go back to an even more boring diet back at home.

This raises the question of campaign length, an important consideration when stockpiling.  Is there any reason to suppose Xerxes though he would be campaigning for more than 180 days from start to finish?  He may even have been optimistic and thought everything would be over in 90 days.  Let us say that he took the cautious option and stocked for 180: that makes about 540,000 tons of grain and whatever would have been deemed necessary for fodder.

540,000 tons sounds like a lot, but these days Kansas alone produces 10.8 million tons a year.  What we are essentially looking at is whether the Persian Empire could move 135,000 tons of grain per year in preparation for this event.  I do not see any problem: most movement would be done by water, in vessels of 50 or 100 ton capacity, requiring a maximum of 2,700 sailings over a year or 450 per safe-sailing month.  Not, I would have thought, an insuperable burden for an Empire which can field 3,000 ships for the actual camapign.  Even adding the same again for fodder leaves most of the ships free to do their thing suring the buildup period, i.e. a lot of slack capacity available.

So on the face of it, the logistics do not look too daunting.

[Patrick Waterson]

Just sorting out the link for this dissertation for Anthony.  (It needed an = between url and http.)

Mark Kindrachuk and yours truly discussed Maurice's paper, on which this seems to be based, extensively in the Lost Battles Yahoo group a few years ago.  What emerged was that Maurice was estimating routes and logistics based on the Gallipoli penisnula and its environs in AD 1920 (following much distortion and depletion of the environment during World War 1) and not the conditions of 480 BC, making his work interesting but of very limited usefulness (a bit like doing a terrain analysis of the suitability of Flanders for mediaeval mounted combat based on the existing terrain directly after Passchendaele).

[Jim Webster]

1. Growing food for 3 - 4 years should do the trick. The biblical account of Egypt storing food during seven years of plenty to be distributed during seven years of famine is IMHO founded on something factual: if nothing else the practical possibility of keeping grain from spoiling for several years. I suspect putting it in large rooms then sealing the rooms completely would work. Remember the grain found in Egyptian tombs after thousands of years? It was still edible.

there are a lot of legends about Egyptian grain. Virtually none of them true

https://www.howplantswork.com/2009/12/28/plant-mythbusters-1-seeds-from-ancient-egyptian-tombs-that-germinate/

[Justin Swanton]

1. Growing food for 3 - 4 years should do the trick. The biblical account of Egypt storing food during seven years of plenty to be distributed during seven years of famine is IMHO founded on something factual: if nothing else the practical possibility of keeping grain from spoiling for several years. I suspect putting it in large rooms then sealing the rooms completely would work. Remember the grain found in Egyptian tombs after thousands of years? It was still edible.

there are a lot of legends about Egyptian grain. Virtually none of them true

https://www.howplantswork.com/2009/12/28/plant-mythbusters-1-seeds-from-ancient-egyptian-tombs-that-germinate/

Germinate, unlikely. Edible, yes.

[Jim Webster]

1. Growing food for 3 - 4 years should do the trick. The biblical account of Egypt storing food during seven years of plenty to be distributed during seven years of famine is IMHO founded on something factual: if nothing else the practical possibility of keeping grain from spoiling for several years. I suspect putting it in large rooms then sealing the rooms completely would work. Remember the grain found in Egyptian tombs after thousands of years? It was still edible.

there are a lot of legends about Egyptian grain. Virtually none of them true

https://www.howplantswork.com/2009/12/28/plant-mythbusters-1-seeds-from-ancient-egyptian-tombs-that-germinate/

Germinate, unlikely. Edible, yes.

The egyptian storage techniques largely depended on extreme dryness and keeping out rodents and insect pests
If you can download it https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1439-0418.1985.tb02787.x could be interesting but all I can read is the abstract
The problem is, to feed armies of the Empire, unless you're campaigning in Egypt, you're going to have to transport it out of Egypt and store it for several years in Asia minor.
Given you're transporting it in small boats, the grain is going to become more moist. Given these ships seem to have rarely carried more than a couple of hundred tons at this time, everywhere is going to be close to the water.
Similarly in Asia Minor,  getting it dry again given the rainfall and temperatures of the areas you were storing it was going to be difficult.
If you want to know the sort of things you have to do to store grain in Europe now
https://cereals.ahdb.org.uk/media/189349/g13_the_grain_storage_guide_-_2nd_edition.pdf

[Erpingham]

So on the face of it, the logistics do not look too daunting.

I'm glad you think so.  Most people who have considered the problem seem to have thought otherwise. 

On the Maurice stuff, do you have evidence of this massive, terrain shattering effect on WWI in northern Greece?  The Gallipoli penninsular was heavily fought over some years before the research but was the war as intensive as Flanders on that front?  Also, it should be noted that total devastation even on the Western Front was fairly confined - I suspect that this argument is a red herring.  More interesting would be climate and land use change since Xerxes invasion.  This would have an effect on the water supply, the amount of forest cover etc.

I'm glad we have re-instated the baggage train.  Living from day to day would have been rather precarious.  Sealift command now has some chance of co-ordinating its efforts into a series of jumps which ships can be tasked to go to as they leave Greece (you can only redirect them at the loading or unloading end).  However, a one-week supply needs a huge train. 

Water supply will continue to be a huge problem, both in absolute terms and access without fouling.

[Dangun]

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

No. This was debunked in the early 20th century?

[Patrick Waterson]

Thanks for that, Jim.

Sadly none of these studies seem to consider the keeping qualities of grain stored in sealed amphorae, which would have been the usual manner of transport.

On the Maurice stuff, do you have evidence of this massive, terrain shattering effect on WWI in northern Greece?  The Gallipoli peninsula was heavily fought over some years before the research but was the war as intensive as Flanders on that front?

Just take a look at the road net on the Gallipoli peninsula c.1920, which was a leftover from the network supplying Turkish forward positions and batteries in 1915-16.  Compare it with the road net today (where coincidentally the main route seems to follow exactly that of Xerxes).  Note the differences.

Northern Greece was not seriously affected by 'terrain shattering' in WW1 - the terrain fought over was mainly shatter-proof mountains - but the road net was temporarily changed as instead of comunicating between Bulgaria and Greece it was diverted to serve positions on the frontier.  This would not have had the same degree or nature of effect on Maurice's perceptions and conclusions as did the Gallipoli road net and the submergence of the plain of Doriscus in the intervening centuries.  Lacking a present-day Doriscus and its environs, historians have come up with weird and wonderful locations for Xerxes' army and its route.

Also, it should be noted that total devastation even on the Western Front was fairly confined - I suspect that this argument is a red herring.  More interesting would be climate and land use change since Xerxes invasion.  This would have an effect on the water supply, the amount of forest cover etc.

Both are significant, in that Maurice seems to have been misled into assuming that the routes followed by Turkish ammunition supply parties in AD1915-16 would have been the route followed by Xerxes' army in 480 BC.  Land use change is a valid point, as I suspect the replacement of Biblical-classical agriculture by Ottoman neglect and the rising of the western and eastern Aegean coastlines plus the gradual submergence of the northern Aegean coastline will have worked changes, those imposed by nature being perhaps greater than those inflicted by man.  The essential point is that Maurice was not working from a 480 BC environment and we therefore cannot use his conclusions as proof of Persian army size.

I'm glad we have re-instated the baggage train.

Not sure we ever lost it, particularly considering its size, which would make it rather hard to lose.   We were just taking the topic one aspect at a time.

Sealift command now has some chance of co-ordinating its efforts into a series of jumps which ships can be tasked to go to as they leave Greece (you can only redirect them at the loading or unloading end).

It looks as if such 'jumps' were planned, given that when the army reached Thermopylae the fleet was waiting for them.

However, a one-week supply needs a huge train. 

Water supply will continue to be a huge problem, both in absolute terms and access without fouling.

These are the next two considerations.  Water is the major limiting factor, and it is interesting to see what Herodotus says about this.

"When he had arrived at Therma, Xerxes quartered his army there. Its encampment by the sea covered all the space from Therma and the Mygdonian country to the rivers Lydias and Haliacmon, which unite their waters in one stream and so make the border between the Bottiaean and the Macedonian territory. In this place the foreigners lay encamped; of the rivers just mentioned, the Cheidorus, which flows from the Crestonaean country, was the only one which could not suffice for the army's drinking but was completely drained by it." - Herodotus VII.127

Access without fouling is a matter of discipline and organisation, but even fouled water is better than no water.  The encamped Persian army seems to have spread itself along rivers where possible, maximising access and minimising mutual interference.

"That is the number of Xerxes' whole force. No one, however, can say what the exact number of cooking women, and concubines, and eunuchs was, nor can one determine the number of the beasts of draught and burden, and the Indian dogs which accompanied the host; so many of them were there. It is accordingly not surprising to me that some of the streams of water ran dry." - idem VII.187

So the army was large enough to deplete some of the smaller Greek rivers, not necessarily of every last drop, but to the point where the flow effectively stopped.  Drinking rivers dry is not a regular occurrence.

The baggage train is harder to assess without a good idea of individual animal carrying capacity and food and water requirements (e.g. how much water does a camel need in northern Greece?).  We can however make some very approximate estimates.  The Wikipedia section on animal loads mentions 330-800 lbs for mules and c.660 lbs for camels.  If we take c.500 lbs per animal we are probably on the safe side, although we should bear in mind bulk as well as weight.

Having earlier roughed out the total daily food requirement for Xerxes' army as around 3,000 tons, one week's supply would be around 21,000 tons.  Allowing five animals to carry a ton, that makes 105,000 baggage animals to serve 3.4 million humans, 80,000 horses and themselves for the stated period of time.  We should perhaps add meat on the hoof, assuming the issue of a meat ration once per week (no evidence for or against this, but let us add it in anyway).  The Greek rule of thumb was that one ox serves 50 men, so to feed 1.7 million (the issue presumably being restricted to fighting men) it would take 34,000 oxen to provide the proposed weekly meat serving.  These totals for animals are surprisingly modest, considering the army size (and if my assumptions and/or calculations are in error someone will doubtless point it out).  Adding in a full fodder estimate triples the number of baggage animals to 315,000 or so, a massive train but not impractical for an army used to this sort of thing.

The logistics are actually looking remarkably practicable.  Huge, requiring a lot of organisation and coordination, but practicable.

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

No. This was debunked in the early 20th century?

Not debunked; rather utterly mishandled by writers thinking in terms of 18th century supply depots.  Hence we need a fresh look at the subject, going back to basics.

[Jim Webster]

Thanks for that, Jim.

Sadly none of these studies seem to consider the keeping qualities of grain stored in sealed amphorae, which would have been the usual manner of transport.

Not really, to quote The logistics of the roman army at war 264BC to AD 235 
Under ancient conditionsm, grain could be stored in three ways, 1 piling it directly onto the floor, 2 confining it in bins or 3, stacking in bags or sacks. Heaping up the grain used all the space in the granary but made it difficult to rotate the old and new stock. If one stored frain in timber bins the loss of storage area is quite significant, around 30% and no evidence of such bins is found in excavated sites. Storing grain in sacks would have been the most practical and convenient method, particularly from the army's perspective. Although there is about a 15% loss of storage space if grain is stored in sacks, the turnover of stock is much easier. In addition the space between the sacks facilitates the dissipation of water vapour and heat and keeps the grain cooler and drier.

[Dangun]

What emerged was that Maurice was estimating routes and logistics based on the Gallipoli penisnula and its environs in AD 1920 (following much distortion and depletion of the environment during World War 1) and not the conditions of 480 BC, making his work interesting but of very limited usefulness

I think this is a misrepresentation of Maurice (1930)'s argument, and I apologise if I have said this in another thread. But...

He gave a long list of reasons why the Herodotus number is not credible. A few of which are:

10. He discusses the area required for an army to camp, using modern examples, and compares it to the historical area available for the Persians to camp in.

11. He discusses the very interesting issue of water distribution - and camps are limited in size by the requirement of troops to be able to walk from the centre of the camp to a water source and back within a day, if the camp is to be sustainable

20. He discusses the volume of water required per day, again using modern examples, and the lack of sufficient sources

21. He discusses the available water sources and the feasible rates of water capture including the issues of waste and fouling

24. He discusses the longest stretches of the Persian march across which water must be carried, again limiting the size of an army (this is also discussed at length in the excellent Engels, 1976, re: Alexander)

25. Maurice discusses the bottle necks on route and the maximum width of the march column, and very interestingly the knock-on effects of pack animals checking up hill and the stress this puts on infrastructure

35 & 38. Maurice discusses the spacial problems of column length

40. Maurice discusses the timing issues, leaving and arriving, whilst also accomodating breaks of very large troop masses

42. Maurice discusses the limiting factor of bridge crossing speed

He also goes in to all sorts of details about port location, coastal access, defiles etc. etc.

Any one of his arguments can be disputed and his assessment of the route can be disputed. But his arguments are in aggregate extensive and I think reasonable in structure. Very few of his arguments are impacted by the changing vegetation of the region.

At the end of the day, to believe the Herodotus number, we are accepting as fact a troop mobilization so large that it would not be repeated for another 2400 years, and when it was in 1914, it made extensive use of rail,  modern manufacturing and a smattering of combustion engines. Germany in 1914 was worried about "squeezing" 625,000 men through a 19km gap when entering Belgium.

I am happy to send anyone a PDF copy of Maurice (1930) if you like, its widely available, and off copyright.

[Erpingham]

Talking of pdfs, and remembering the need to introduce novelty, have we had this article before?  A warning though - it is scanned upside downand backwards.  You will need to print and reassemble it.

[Justin Swanton]

What emerged was that Maurice was estimating routes and logistics based on the Gallipoli penisnula and its environs in AD 1920 (following much distortion and depletion of the environment during World War 1) and not the conditions of 480 BC, making his work interesting but of very limited usefulness

I think this is a misrepresentation of Maurice (1930)'s argument, and I apologise if I have said this in another thread. But...

He gave a long list of reasons why the Herodotus number is not credible. A few of which are:

10. He discusses the area required for an army to camp, using modern examples, and compares it to the historical area available for the Persians to camp in.

11. He discusses the very interesting issue of water distribution - and camps are limited in size by the requirement of troops to be able to walk from the centre of the camp to a water source and back within a day, if the camp is to be sustainable

20. He discusses the volume of water required per day, again using modern examples, and the lack of sufficient sources

21. He discusses the available water sources and the feasible rates of water capture including the issues of waste and fouling

24. He discusses the longest stretches of the Persian march across which water must be carried, again limiting the size of an army (this is also discussed at length in the excellent Engels, 1976, re: Alexander)

25. Maurice discusses the bottle necks on route and the maximum width of the march column, and very interestingly the knock-on effects of pack animals checking up hill and the stress this puts on infrastructure

35 & 38. Maurice discusses the spacial problems of column length

40. Maurice discusses the timing issues, leaving and arriving, whilst also accomodating breaks of very large troop masses

42. Maurice discusses the limiting factor of bridge crossing speed

He also goes in to all sorts of details about port location, coastal access, defiles etc. etc.

Any one of his arguments can be disputed and his assessment of the route can be disputed. But his arguments are in aggregate extensive and I think reasonable in structure. Very few of his arguments are impacted by the changing vegetation of the region.

At the end of the day, to believe the Herodotus number, we are accepting as fact a troop mobilization so large that it would not be repeated for another 2400 years, and when it was in 1914, it made extensive use of rail, the combustion engine, modern manufacturing and a smattering of combustion engines. Germany in 1914 was worried about "squeezing" 625,000 men through a 19km gap when entering Belgium.

I am happy to send anyone a PDF copy of Maurice (1930) if you like, its widely available, and off copyright.

I'd be interested. justinswanton@gmail.com