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

[Justin Swanton]

I dispute Gallipoli. I mapped out a route that allows for a wide column to move up the peninsula. Shall I post photos?

no, could we have a contour map please, they're far easy to read than photos

Jim

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

[Jim Webster]

I dispute Gallipoli. I mapped out a route that allows for a wide column to move up the peninsula. Shall I post photos?

no, could we have a contour map please, they're far easy to read than photos

Jim

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

You were talking about having to have these men advance on a 600m  front, 300 men abreast.
Given that a lot of the valleys, from crest to crest, are less that 2km wide, I see rather more choke points than you do I'm afraid. Even after checking it on google maps with the satellite view it doesn't look any better

[Flaminpig0]

Please, the Achaemenid Empire was Biblical rather than semi-feudal (whatever that is supposed to mean, but I get the impression of 'disorganised' and 'primitive').

You would be getting the wrong impression.

[Dangun]

I have been thinking more about the scalability of camps, and the factors that limit them.

For example water supply.
If we imagine a water hole that is 10m in diameter and supplies an infinite amount of unfoulable water.
Assuming: 1) a man needs 5minutes to drink and fill his water bottle for the day; and 2) will occupy 1m of the circumference of the water hole when drinking, then the water hole can support only 9040 soldiers. Moreover, they would be a very sad bunch of soldiers because they would have to stay at the water hole permanently, not having the time to leave and do anything as a unit.

If an army of 3million is to be watered by such a watering hole, making the same assumptions, then the watering hole would have to have a diameter of 3.3km. Now you still have the problem of the army being incapable of moving as a whole during the day. But you have another problem, a water hole this large will have a circumference of 10.4km, any single soldier would spend the day walking across the camp.

If you want to water the army faster, so that they can say... march somewhere, then the  water hole has to be bigger, but then you have the problem that the water hole is so big it is an obstacle that the army can't walk around in day without needing to return to it to drink.  They get stuck!

It does NOT scale.

OK, maybe we like rivers instead. But the maths is no more appealing.
Assuming every soldier needs 5 minutes a day to drink and fill his canteen, of a 3million person army, a minimum of 10,416 will be drinking at any one moment. If they need 1m of riverbank to do this, then your army must be stretched over a minimum of 10.4km of river AT ALL TIMES, just to be watered. If you actually want to do something like fight, go elsewhere, etc. then it gets even sillier.

[Prufrock]

Assuming every soldier needs 5 minutes a day to drink and fill his canteen, of a 3million person army, a minimum of 10,416 will be drinking at any one moment. If they need 1m of riverbank to do this, then your army must be stretched over a minimum of 10.4km of river AT ALL TIMES, just to be watered. If you actually want to do something like fight, go elsewhere, etc. then it gets even sillier.

Yes, water is a big issue, and again, I think Maurice is valuable here in that he had direct experience of the time and space (and other considerations) needed to do things like fill up the water bottles and water the horses when there are large numbers of troops, whereas we armchair warriors do not!

[Prufrock]

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

Looking at in on google earth and walking the ground are different things. Even if they are able to walk across hills rather than use tracks, men and horses will need to chose their route constantly, which creates congestion, and when you've got 2 million men following behind you there are going to be massive jams, long periods of no movement, and fights breaking out as people jostle each other. Some fall down and are trampled to death; crowd dynamics come into play. On top of all that, units lose their cohesion, men become separated from their commanders and animals; they lose access to their food and water supplies; they don't get orders.  It would be a disaster.

[Justin Swanton]

I dispute Gallipoli. I mapped out a route that allows for a wide column to move up the peninsula. Shall I post photos?

no, could we have a contour map please, they're far easy to read than photos

Jim

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

You were talking about having to have these men advance on a 600m  front, 300 men abreast.
Given that a lot of the valleys, from crest to crest, are less that 2km wide, I see rather more choke points than you do I'm afraid. Even after checking it on google maps with the satellite view it doesn't look any better

This is where the contours matter. Those valleys have slopes at angles of 1 in 10 or less - they can easily be walked along. The army needs a width of about 600m only, not 2000m.

[Justin Swanton]

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

Looking at in on google earth and walking the ground are different things. Even if they are able to walk across hills rather than use tracks, men and horses will need to chose their route constantly, which creates congestion, and when you've got 2 million men following behind you there are going to be massive jams, long periods of no movement, and fights breaking out as people jostle each other. Some fall down and are trampled to death; crowd dynamics come into play. On top of all that, units lose their cohesion, men become separated from their commanders and animals; they lose access to their food and water supplies; they don't get orders.  It would be a disaster.

Which would make migrating tribes like the Helvetii ambulating accidents. 

Seriously though, if the ground is pretty flat, has been cleared of obstacles like difficult vegetation beforehand, everyone walks reasonably spaced from each other (like a normal army on the march), what real problems could there be?

[Justin Swanton]

I have been thinking more about the scalability of camps, and the factors that limit them.

For example water supply.
If we imagine a water hole that is 10m in diameter and supplies an infinite amount of unfoulable water.
Assuming: 1) a man needs 5minutes to drink and fill his water bottle for the day; and 2) will occupy 1m of the circumference of the water hole when drinking, then the water hole can support only 9040 soldiers. Moreover, they would be a very sad bunch of soldiers because they would have to stay at the water hole permanently, not having the time to leave and do anything as a unit.

If an army of 3million is to be watered by such a watering hole, making the same assumptions, then the watering hole would have to have a diameter of 3.3km. Now you still have the problem of the army being incapable of moving as a whole during the day. But you have another problem, a water hole this large will have a circumference of 10.4km, any single soldier would spend the day walking across the camp.

If you want to water the army faster, so that they can say... march somewhere, then the  water hole has to be bigger, but then you have the problem that the water hole is so big it is an obstacle that the army can't walk around in day without needing to return to it to drink.  They get stuck!

It does NOT scale.

OK, maybe we like rivers instead. But the maths is no more appealing.
Assuming every soldier needs 5 minutes a day to drink and fill his canteen, of a 3million person army, a minimum of 10,416 will be drinking at any one moment. If they need 1m of riverbank to do this, then your army must be stretched over a minimum of 10.4km of river AT ALL TIMES, just to be watered. If you actually want to do something like fight, go elsewhere, etc. then it gets even sillier.

Water just takes a little organisation. If a squatter camp of 6000 people can get all its water requirements from just 2 taps then a large army on the move can manage. It doesn't take 5 minutes to drink one's fill of water and fill a canteen.

[Jim Webster]

I dispute Gallipoli. I mapped out a route that allows for a wide column to move up the peninsula. Shall I post photos?

no, could we have a contour map please, they're far easy to read than photos

Jim

Here it is. A rather large pdf file. Once you open it you need to zoom in. Contours are at 20m intervals. I see only one potential chokepoint at a now-existing dam. I've included a photo to give an idea of how difficult the chokepoint is. It doesn't seem that difficult.

You were talking about having to have these men advance on a 600m  front, 300 men abreast.
Given that a lot of the valleys, from crest to crest, are less that 2km wide, I see rather more choke points than you do I'm afraid. Even after checking it on google maps with the satellite view it doesn't look any better

This is where the contours matter. Those valleys have slopes at angles of 1 in 10 or less - they can easily be walked along. The army needs a width of about 600m only, not 2000m.

have you ever marched a column 300 men wide when the column was both climbing AND the men were were marching along a slope?
What speed did they manage?
I've done enough fell walking to know that on the sort of rough terrain you see on the satellite image you're going to have a mob because nobody will be able to keep in ranks for more than a few yards

Have you any examples of armies marching through hill country in columns 300 men across? For days

[Jim Webster]

Water just takes a little organisation. If a squatter camp of 6000 people can get all its water requirements from just 2 taps then a large army on the move can manage. It doesn't take 5 minutes to drink one's fill of water and fill a canteen.

the difference is in the name. Nobody in the squatter camp is going anywhere (hence squatters)
Maurice, who actually knew how these things were done, was talking about damming the river to create pools to allow men to fill containers more quickly

[Patrick Waterson]

Sicily was never the granary of the Med, it  topped up Rome. By the time it became important again (after the loss of Africa) it was mainly because church lands there were being used by the church to support the decreasing Roman population.

And neither was Cyrenaica, but both are noted in classical sources as being wonderfuly fertile.

But if you want to invent a golden age of Greek agriculture when it could outproduce what it does now in a desperate attempt to prop up the theory, feel free

Except am not inventing it, simply describing what sources have written.  Incidentally, have you assessed the effects of industrialisation, mechanisation, two world wars and the EU agricultural policy on animal numbers in Europe in general and Greece in particular?  You cannot just use today's numbers as a basis for what an area could support in 480 BC.

have you ever marched a column 300 men wide when the column was both climbing AND the men were were marching along a slope?
What speed did they manage?
I've done enough fell walking to know that on the sort of rough terrain you see on the satellite image you're going to have a mob because nobody will be able to keep in ranks for more than a few yards

But a mob moving at a reasonable speed, especially when a significant proportion of the men concerned themselves come from hilly and mountainous areas.  And they will keep up their speed as long as the whip-men have breath.

Have you any examples of armies marching through hill country in columns 300 men across? For days

What we do have is examples of more recent armies moving tens of thousands of men through much worse country in a way British staff believed could not be done.  The Kohima/Imphal campaign is not a bad illustration of this.  The point is that the way we look at a situation is not necessarily the best or only way that situation can be handled.

In any event, if one gets past a potential choke-point in a rough and ready fashion rather than in immaculate formation, one is still past it.

[Patrick Waterson]

I have been thinking more about the scalability of camps, and the factors that limit them.

For example water supply.

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Assuming every soldier needs 5 minutes a day to drink and fill his canteen, of a 3million person army, a minimum of 10,416 will be drinking at any one moment. If they need 1m of riverbank to do this, then your army must be stretched over a minimum of 10.4km of river AT ALL TIMES, just to be watered. If you actually want to do something like fight, go elsewhere, etc. then it gets even sillier.

But if you have camp followers who each draw water for several people at the same time, using a waterskin ...

... and if they fill the skins before the army (or their particular part of the army) sets off, they can be fulfilling needs during the day, like the bhistis of an Indian army.

One can also get camp followers to dig watering trenches for the army's animals; if the ground is clean enough, additional channels of this nature can also be used by the men, vastly increasing the available access interface.

Small efficiency factors like this can make a huge difference.  And one does need to consider them.

[Jim Webster]

there is a limit to how much time I'm willing to waste

So now Patrick sees that Persian army as a whip driven mob up to six million strong if you include baggage etc

We're also assured that they were so well organised that you could water all of them from two taps, and this whip driven mob camped with a tightness and discipline that the Imperial Roman army would have admired

On top of this, they passed through a land which whilst now a little desolate, was in reality a land of milk and honey which could carry stocking rates for livestock an order of magnitude higher than can be done today, even though the same land was known at the time to be so dry the rivers got very low in summer

To feed this whip driven mob the Persians invented grain storage techniques nobody in the world has used before or since.

It is getting beyond silly. Fatuous got embarrassed and left some time ago. We have people who have never seen an area looking at photos and deriding the comments of men who walked the ground and who had had to move armies.
I'm getting sick of wasting my time digging up genuine evidence only to have it dismissed by get another bout of 'handwavium.

Look, there are some simple things you can do.

Go to Xenophon. He lived in a Persian army camp for months. See how he described them both in his Cyropaedia and his Anabasis
Come back and quote that as evidence to support your case
Then you have his march to the sea through rough country. Give that as an example of how it was easy for heavy infantry to march 

[Erpingham]

Could I just check how the army is carrying its non-food supplies e.g. the large numbers of arrows it needs?  Are we assuming that these are being carried by the camp followers (disregarding those on special duties)?