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

[Erpingham]

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

I think this is one of those times Jim calls "hand wavium".  Just because you can multiply up the figures doesn't make them practicable, it just makes them visualisable. 

There are many practical issues with the idea of an army of 3.4 million men and 315,000 animals operating effectively in the campaign area.  Aaron lists many of them, which can't really be just dismissed by the fact that the road grid was different in the 1920s. 

I suspect we can't dismiss all the works on estimating the size of the Persian army done in the last 100 or so years as "mishandling" the evidence.   

[Patrick Waterson]

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

Just because you can multiply up the figures doesn't make them practicable, it just makes them visualisable. 

Which brings us to the question of practicability.  What actually makes large numbers impracticable?

There are many practical issues with the idea of an army of 3.4 million men and 315,000 animals operating effectively in the campaign area.  Aaron lists many of them, which can't really be just dismissed by the fact that the road grid was different in the 1920s.

Actually it is Nicholas, not Aaron, but I am sure he will forgive you.   I have a copy of Maurice's work buried somewhere in my files, and remember being less than impressed with his British Army staff calculations - as was T E Lawrence when some very similar staff figures were used to plan a raid by his Arab forces; he introduced modifications based on practical experience and slashed the logistical requirement to about a third of the calculated figure.

Maurice seems to assume that Xerxes' army had the establishment, scale of equipment and practices of a First World War army.  This is not an encouraging starting-point, and his use of early 20th century road nets is less helpful still.  The geographic changes since 480 BC will also have had an impact, though in which direction is not immediately evident, but what is evident is that part of Xerxes' route through the Thracian coastal plain has been lost to the sea, which renders inoperative many of Maurice's march and hydraulic calculations.  I cannot claim to have correct figures myself, but we should be aware that Maurice's are in error by a couple of millennia.

I suspect we can't dismiss all the works on estimating the size of the Persian army done in the last 100 or so years as "mishandling" the evidence.

Perhaps not. But any based on an 18th century depot system and associated calculations can safely be disregarded.

[Dangun]

I'd be interested. justinswanton@gmail.com

Will send it tonight. Sadly can't send attachments from work.

[Jim Webster]

I'd be interested. justinswanton@gmail.com

Will send it tonight. Sadly can't send attachments from work.

I'd be interested as well, jwebster2@btconnect.com
But if it's out of copyright could you just attach the pdf to the thread?

[Andreas Johansson]

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

I'd be happy for a copy too
andreasj at gmail dot com

[Andreas Johansson]

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.

Many pdf readers can helpfully rotate the view for you

[Justin Swanton]

The point about road grids is I suspect a bit misleading. If a Persian army of 3,4 million men was going to march through Thrace and Macedonian and into Greece, it couldn't use roads. It had to march cross-country, in several columns a hundred or more abreast or one column several hundred abreast, if it was to move from campsite to campsite in a single day.

I don't see any real problem with this until one reaches serious mountains. If the Persians spent several years in preparation, going as far as to dig a canal so their fleet wouldn't have to risk a storm, then they would surely have been able to clear a broad, rough avenue - trees and undergrowth gone, rocky obstacles cleared away if they couldn't be gone around. Not real roads of course. My little virtual journey in Google Earth didn't reveal any serious obstacles to broad avenues before reaching Greece proper. Sure, there would have been a fair bit of hiking over hills without the benefit of beaten tracks (I've done it - not much fun) but nothing unduly onerous. The supply wagons would of course get the best ground going through chokepoints.

[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.

Many pdf readers can helpfully rotate the view for you

But strangely couldn't in this case.  They also can't reverse the page order (unless you have the expensive paid-for ones)

[Patrick Waterson]

As Justin indicates, back then armies did not march along roads for the simple reason there were no roads as we understand them except for the Royal Persian Highway, a comparatively narrow paved track used by galloping messengers.  Armies used routes.  This meant they travelled along a much wider frontage than Maurice's column of fours, and they often followed established transit lanes regularly tramped by merchants, livestock etc.

Choke points such as mountain passes were another matter.  Assyrian procedure was to get the wheeled transport up the pass while the troops themselves scaled the more accessible parts of the mountains (a bit like Spartan armies habitually climbing Mount Cithaeron).  I am not sure what approach the Achaemenids adopted but the Assyrian procedure was probably not unknown to them.  Medes and Mesopotamians had been moving armies through mountainous areas more or less since Medes were invented.

This way of doing things would bring them past the chokepoint rather more rapidly than 20th century calculations, which assume everything tramps through the pass, will allow.

The degree of preparation for crossing such chokepoints is also significant.  Most literature I have seen on the subject seems to assume that the Achaemenid army would be encountering new and unknown terrain and traversing it the hard way.  In practice, the Persians had ample opportunity to spy out the land beforehand: remember all those ambassadors criss-crossing Greece demanding earth and water?  (The Spartans put theirs into a well and told them to take as much as they liked.)  They would have had ample opportunity to note routes, geography and potential holdups, and the transit of the Persian army from Doriscus to Thermopylae looks remarkably well planned, including felling their way through part of Macedonia and still arriving on time.

[Jim Webster]

I'm just in awe of the sanitary arrangements.  On average an adult produces 2.2 lbs (0.998kg) of urine and 0.5 lbs (0.227 kg) of fecal matter a day. That's nearly a thousand tons of urine per million men and about 230 tons fecal matter.Then the livestock would produce more.
At the choke points (the bridge for example) everybody would have to follow much the same road
It apparently took the army seven days and seven nights to cross the bridge, so more normal choke points probably didn't have night marching so perhaps 14 days. But it means that each camp site and days march would get perhaps 14,000 tons of urine and 3200 tons of fecal matter.
Now some would be spread along the road, depending on how strong march discipline was.
But I'd guess that we'd probably still be able to detect the armies passing by the soil fertility 
After all they've found traces of Hannibal's army in a peat bog in the Alps.

[Justin Swanton]

I'm just in awe of the sanitary arrangements.  On average an adult produces 2.2 lbs (0.998kg) of urine and 0.5 lbs (0.227 kg) of fecal matter a day. That's nearly a thousand tons of urine per million men and about 230 tons fecal matter.Then the livestock would produce more.

If the army is divided and laterally spread out so the column length(s) are no longer than those of a regularly sized army then the sanitation problems are no worse than for the 'regular' army.

At the choke points (the bridge for example) everybody would have to follow much the same road
It apparently took the army seven days and seven nights to cross the bridge, so more normal choke points probably didn't have night marching so perhaps 14 days. But it means that each camp site and days march would get perhaps 14,000 tons of urine and 3200 tons of fecal matter.

The bridge over the Hellespont was the only true single chokepoint of the entire expedition. Other chokepoints all the way to Greece proper were not formidable - they could be crossed by men on either side of the chokepoint pass whilst wagons passed through the middle, and the army could (and did) divide into several columns so only a fraction had to pass through any single chokepoint.

Now some would be spread along the road, depending on how strong march discipline was.
But I'd guess that we'd probably still be able to detect the armies passing by the soil fertility 
After all they've found traces of Hannibal's army in a peat bog in the Alps.

Has anyone looked for traces of the Persian passage through Thrace and Macedonia?

[Erpingham]

We seem to be drifting into a "A Persian Army could traverse difficult terrain therefore it was 3,500,000 strong" argument.  I don't think anyone denies the historicity of the army carrying out its march.

As to whether staff officers calculations are correct, we should perhaps recall they had moved horse-powered armies in the field and we have not.  So, yes, they will fall into the trap of thinking that the way they were taught is the only way to do it.  But to them, it wasn't just multiplying numbers on pieces of paper - they actually moved large bodies of soldiers.  And suggesting TE Lawrence could move armies with 1/3 the supplies doesn't entirely help when the proposed army is ten to twenty times that which these dismissed professionals thought plausible.

[Jim Webster]

I'm just in awe of the sanitary arrangements.  On average an adult produces 2.2 lbs (0.998kg) of urine and 0.5 lbs (0.227 kg) of fecal matter a day. That's nearly a thousand tons of urine per million men and about 230 tons fecal matter.Then the livestock would produce more.

If the army is divided and laterally spread out so the column length(s) are no longer than those of a regularly sized army then the sanitation problems are no worse than for the 'regular' army.

Perhaps then you can give us an example of a regular army that put 1.8 million men, plus perhaps two or three times that number of camp followers plus however many hundreds of thousands of head of livestock across a single bridge in a seven day period?

[Mark G]

I am beginning to wonder if this is not a prolonged April fool.

We have parties who to profess to a faith position on the accuracy of ancient texts calling for evidential proof that the texts are right, and then dismissing any evidential proof that demonstrates doubt / proof of impossibility.

And the basis for the dismissal essentially boils down to a refusal to accept any evidence that is more recent than the ancient texts or is itself not an ancient text , or something modern that supports their faith position.

Deeply ironic.

No yellow image needed

[Duncan Head]

Perhaps then you can give us an example of a regular army that put 1.8 million men, plus perhaps two or three times that number of camp followers plus however many hundreds of thousands of head of livestock across a single bridge in a seven day period?

Two bridges, be fair - one for the 1.8 million men, the other for the camp followers, livestock, etc. 50% less impossible