Ancient Military Manpower

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Volyn
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Ancient Military Manpower

Post by Volyn » 23 Oct 2020 23:14

In an era when blades, bows and shields were the main weaponry of war, how large would a civilization's general population need to be in order to raise an army of 30,000 - 50,000 soldiers?

Does anyone know what the ratio was between combat arms and support personnel for a military force that size?

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Sheldrake
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Re: Ancient Military Manpower

Post by Sheldrake » 24 Oct 2020 11:03

Volyn wrote:
23 Oct 2020 23:14
In an era when blades, bows and shields were the main weaponry of war, how large would a civilization's general population need to be in order to raise an army of 30,000 - 50,000 soldiers?

Does anyone know what the ratio was between combat arms and support personnel for a military force that size?
It depends on the context.

An agricultural society could mobilise all able bodied men of fighting age for a short period of time depending on the time of year. After the harvest and before ploughing is good. Quality of manpower and equipment might vary between an ill armed mob and the hoplites of the city states of ancient Greece. Standing armies could only be supported by a huge Empire such as the Romans, Persians or Chinese. A warrior caste such as feudal knights were equipped to fight and supported by men at arms and archers, but usually dispersed to protect/ rule their own lands.

Armies of 30-50,000 are sometimes mentioned in ancient texts, It is a big number. There is a lot of debate about the size of the armies and casualties at the Battle of Towton 1461, alleged to be the most bloody battle on English soil
http://www.battlefieldstrust.com/resour ... FieldId=46

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Re: Ancient Military Manpower

Post by Volyn » 24 Oct 2020 22:00

Sheldrake wrote:
24 Oct 2020 11:03
It depends on the context... Armies of 30-50,000 are sometimes mentioned in ancient texts, It is a big number.
Very good, thank you for responding Sheldrake.

If it is possible, I would like to try and determine what a minimum population level would need to be for raising an army in this size range?

If we use the Macedonian army with their hoplites as one example, Alexander the Great had 37,000 soldiers at the Battle of Granicus, at the Battle of Issus he had 41,000 soldiers, at the Battle of Gaugamela he had 47,000 and at the Battle of Hydaspes he also had 47,000. These battles occurred between 334 - 326 BC, and it shows that he was able to maintain this size of a force for an extended period of time.

I have not been able to find an estimate for the ancient Macedonian population, does anyone know what it might have been?

There are also examples of other civilizations that were able to raise military forces approaching these numbers, Muhammad had about 30,000 soldiers at the Battle of Tabuk in 630 AD, and the Aztec Empire supposedly fielded up to 300,000 during the siege of Coixtlahuaca in 1458.
https://www.mexicolore.co.uk/aztecs/ask-us/aztec-army

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Steve
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Re: Ancient Military Manpower

Post by Steve » 24 Oct 2020 22:33

Hello,
In ancient states we can say with certainty that about half their populations were composed of women who were not likely to serve in the army. Of the 50% male population a large proportion would have been to old or to young and maybe a higher proportion than today’s male population would be crippled diseased or whatever.

In WW1 about a quarter of the male British population served in the armed forces. In 1915 there were about 1.5 million men in reserved occupations with more as the war went on. With no reserved occupations maybe Britain could have put a third of its male population into the armed forces. Therefore I am guessing that to raise 50,000 men for an army you need a male population of about 150,000 so a total population of 300,000.

However, as Sheldrake wrote “An agricultural society could mobilise all able bodied men of fighting age for a short period of time depending on the time of year”.

A fairly well documented example of this though from nearer times than you are looking for is the Norman invasion of England in 1066. England’s Harold Godwinson knew an invasion was coming; he called up the English militia and waited on the south coast. The Normans had not invaded by the time the English harvest needed bringing in so the men of the militia were released to bring in the harvest. The Norman army was not largely composed of a peasant militia it was semi professional plus mercenaries so did not have this problem and invaded. Another problem Harold may have had was what to do once his men consumed the food they had brought with them and the food in the area where they were waiting. Again the invading army did not have this problem because as soon as it landed it started ravaging the English countryside but it would have had to move on so as not exhaust the area’s food supplies.The Normans did not need many support personnel since the English would provide everything they needed.

The Norman army has been estimated at maybe 8,000 men and a couple of thousand horses. You cannot estimate what Normandy’s population was from this army because a large proportion were either mercenaries or adventurers from all over France who were promised land in England if things went well. What proportion of Alexander’s men were full time soldiers maybe drawn from all over the Greek world?

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Re: Ancient Military Manpower

Post by Volyn » 25 Oct 2020 17:37

Thank you Steve for your input.
Steve wrote:
24 Oct 2020 22:33
In ancient states we can say with certainty that about half their populations were composed of women who were not likely to serve in the army. Of the 50% male population a large proportion would have been to old or to young and maybe a higher proportion than today’s male population would be crippled diseased or whatever.
This is exactly what I was thinking, ancient warfare required brute strength and physical endurance restricting the actual number of men that could be pressed into service. Who would have been considered fit and healthy enough for military enrolment and what percentage of a population could that number constitute?
Steve wrote:
24 Oct 2020 22:33
In WW1 about a quarter of the male British population served in the armed forces. In 1915 there were about 1.5 million men in reserved occupations with more as the war went on. With no reserved occupations maybe Britain could have put a third of its male population into the armed forces. Therefore I am guessing that to raise 50,000 men for an army you need a male population of about 150,000 so a total population of 300,000.

However, as Sheldrake wrote “An agricultural society could mobilise all able bodied men of fighting age for a short period of time depending on the time of year”.
The only problem with comparing industrial era army numbers is that technology allows for a military to make greater use of its personnel, so the potential usable pool of manpower is increased. If we assume that a total population of 300,000 might be sufficient to raise a force of 50,000 it could only happen in an emergency scenario, and once the crises had passed they would fully demobilize or else their society would face terrible consequences with respect to a failed harvest, etc.
Steve wrote:
24 Oct 2020 22:33
The Norman army was not largely composed of a peasant militia it was semi professional plus mercenaries so did not have this problem... What proportion of Alexander’s men were full time soldiers maybe drawn from all over the Greek world?
If we look at the initial Macedonian army that Phillip II created he made military service a full-time occupation, similar to the Normans. Phillip used this army to subjugate the rest of the Greek city-states, but I do not know what the size of his forces were when he did this. Your question raises a good point, if his son Alexander made use of other Greek soldiers then it would have been enough.

Would it be possible to determine how large a population needs to be in order to sustain a force of 30,000 semi-professional soldiers?

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Re: Ancient Military Manpower

Post by Steve » 26 Oct 2020 03:56

Hello,
A check of the internet came up with a few sites that give Roman Legionary rations and this is perhaps the best guide as to what a Macedonian solder received. It could then be scaled up for the army you are interested in but men can go for a long time on short rations. Also perhaps check out what the daily food ration was for say a British soldier in WW1 this should give an idea of what a soldier of any period needed to stay healthy.

The Confederate army in the US civil war was completely reliant on what the southern states could produce and managed to stay in the field for four years. The population of the Confederacy including slaves seems to have been 9 million. Some armies such as the Mongol did not need any home population to provide food as the men lived off the horse herds they moved with. I would guess that all ancient armies were to a greater or lesser extend expected to live of the land they were moving through. Napoleons army when marching on Moscow augmented their food supplies by extensive foraging seemingly picking the countryside clean along the line of march.

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Re: Ancient Military Manpower

Post by Sheldrake » 26 Oct 2020 11:53

I am not sure about the diet of ancient soldiers, but in medieval and early modern times the diet was heavily weighted towards bread, with other calories obtained from beer and cheese. The cost per calorie was roughly similar. Meat was a luxury - for feast days or the rich. A pound of bread (half kilo) would provide around 2500 Kcal - about 3/4 of those demanded by a labourer. Maybe the rest are from olive oil (100ml) and wine (1/2 Litre)

So an army of 30,000 men would need to find at least 30,000 lb 15 tons of grain, the same of wine and maybe 3 tons of oil. The grain would need to be milled and baked. So there is also a need for firewood and water. A force of 30,000 men is comparable to a city like Jerusalem or Athens. It will need similar services.

The switch from hunter gatherer to grain farmer made it possible to generate food surpluses that could feed non productive individuals such as bureaucrats, traders and soldiers. Grain and olive oil can also be stored to provide food during the winter, or a reserve to cope with famine or stocks to fight a war. So the question is how much grain could land provide over and above that needed to pay for the population to feed its workforce? How much could be stored? How much time between each war? Some food surplus would be in state stores the rest held by households.

There is the option of living off the land. A conquering army can extort food and use the surpluses for the region as it passes through. Alexander could do this on the move as he passed through populous areas. But not when he marched his men across a desert. If an army stayed in one place it would need to be supplied from somewhere.

There is a very good article in the current The Journal of Military History about the French logistics and strategy of the 1709 campaign in Flanders. This includes a lot of detail about grain supplies. France one of the more populous and rich powers struggled to feed its armies. Here were some of the problems:-
The winter of 1708-09 was a very severe and there was famine in 1709
The businesses supplying the army were inefficient and had not been paid
The government was broke and owed money to everyone, including soldiers and the businesses supplying the army
Attempts to seize food by force resulted in revolt.
Transport carts and horses hired/commandeered from local peasants were inadequate for the job.

You might be better looking for answers on a forum which specialises in the ancient world

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Re: Ancient Military Manpower

Post by Volyn » 26 Oct 2020 13:09

I found a website that addresses the sizes of the Roman and Greek armies during the Punic wars, and it contains some other tangentially relevant information about this topic. However, it does not address the actual population size required to raise these forces.

https://en.wikipedia.org/wiki/Battle_of_the_Trebia
For example Hannibal had 30,000 - 40,000 men to fight Rome at the Battle of the Trebia when he entered Italy, with about 50% - 60% of the soldiers estimated to be Carthaginians or from other North African regions.

I found this piece of information to be fascinating:
https://www.reddit.com/r/AskHistorians/ ... antiquity/
In the 19th century, the Prussian General Staff carried out studies, and found that the largest force you could supply along one road entirely with horse pulled wagons was about thirty thousand men... Furthermore, the furthest an ox can pull a cart loaded with grain is about 150-180 km without refilling; at that point, it will have eaten everything in that cart, and there would be nothing left to deliver.
The article has some answers for you Sheldrake:
Sheldrake wrote:
26 Oct 2020 11:53
I am not sure about the diet of ancient soldiers, but in medieval and early modern times the diet was heavily weighted towards bread, with other calories obtained from beer and cheese. The cost per calorie was roughly similar. Meat was a luxury - for feast days or the rich. A pound of bread (half kilo) would provide around 2500 Kcal - about 3/4 of those demanded by a labourer. Maybe the rest are from olive oil (100ml) and wine (1/2 Litre)

So an army of 30,000 men would need to find at least 30,000 lb 15 tons of grain, the same of wine and maybe 3 tons of oil. The grain would need to be milled and baked. So there is also a need for firewood and water. A force of 30,000 men is comparable to a city like Jerusalem or Athens. It will need similar services... There is the option of living off the land. A conquering army can extort food and use the surpluses for the region as it passes through. Alexander could do this on the move as he passed through populous areas. But not when he marched his men across a desert. If an army stayed in one place it would need to be supplied from somewhere... There is a very good article in the current The Journal of Military History about the French logistics and strategy of the 1709 campaign in Flanders. This includes a lot of detail about grain supplies.
Geoffrey Parker explains the supply conditions of 30,000 men in 16th century Europe. The expected daily ration for a soldier was 1.5 lbs of bread and 1 lb of meat/cheese/fish, and six pints of beer. Just for the daily bread, the army would need twenty tons of flour; a week's supply of flour, with ovens and firewood, would take up 250 wagons. Providing 1 lb of meat a day would require the army to slaughter 1500 sheep every day, and that's not including supplies of ammunition, clothes, equipment, fodder, and so on.

A supply route could be stretched further if the troops confiscated supplies from civilians along the way, or carried a greater portion of the supplies on their backs, but there's a point of diminishing returns on this; 30,000 men on the road is about a day's march long, so if something happens at the front of the column, it'll take all day for the guys at the rear to make it to the action. When in friendly territory, an army can also shore up its supply situation by establishing chains of supply depots, where supplies can be stockpiled when not urgently needed; this is how the Spanish were able to repeatedly move tens of thousands of men from Spain to the Netherlands through Italy, France, and Germany in the 16th and 17th century.
There is also an answer for one of Steve's questions:
Steve wrote:
24 Oct 2020 22:33
What proportion of Alexander’s men were full time soldiers maybe drawn from all over the Greek world?
When Alexander the Great led his expedition into Asia, he had just under 40,000 men at the Battle of Granicus; about half of this army came from his kingdom and were professional soldiers, and the other half were allies from all the Greek city states and mercenaries.
Unfortunately I still have not found references for the size of the population in these cities or empires at the time they raised their armies, did the ancient world conduct a census of it's people?

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Re: Ancient Military Manpower

Post by Sheldrake » 26 Oct 2020 14:40


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Re: Ancient Military Manpower

Post by Steve » 26 Oct 2020 21:27

Hello,
Had a quick look at the history of Alexander written by the ancient historian Diodorus but could not find anything about how Alexander fed his army or on population numbers. However I did come across what Diodorus gives for the make up of Alexander’s army and its numbers. The review of the army was seemingly done shortly after landing in Asia.

“Alexander then carried out in person a careful review of the army that was following him. Of the infantry there were counted 12,000 Macedonians, 7,000 allies, and 5,000 mercenaries; Parmenion held command over all these. They were accompanied by 7,000 Odrysians, Triballians and Illyrians, and 1,000 archers and the "Agrianians". In all the infantry numbered 30,000".

Of the cavalry there were 1,800 Macedonians, under the command of Philotas son of Parmenion, 1,800 Thessalians, commanded by Callas son of Harpalus, a total of 600 of the other Greeks, commanded by Erygius, and 900 Thracian scouts and Paeonians, with Cassander as their commander. The total number of cavalry was 4,500.

Such was the size of the army that crossed into Asia with Alexander”.

Diodorus seems to have had a problem with addition as the cavalry total 5,100 not 4,500. There is also a problem with the infantry as 12,000 Macedonians plus the 7,000 allies and 5,000 mercenaries comes to 24,000 and they were accompanied by 7,000 from various nationalities plus 1,000 archers giving a total of 32,000 not 30,000.

Taking Diodorus’s figures at face value it seems that 37.5% of the infantry and 35% of the cavalry was Macedonian.

The information given in previous posts on the problems of supplying armies was informative. Given these problems it would be surprising if after starting his invasion Alexander was relying on provisions reaching him from Greece. Perhaps the Persians maintained supply depots both for their army and in case of famine which were seized and maybe the price of a city being spared was a ransom paid largely in food. As there is no mention (as far as I am aware) of Alexander looting his way across Asia maybe the treasure captured from the Persians enabled him to buy all the provisions needed from the populations passed through.

http://turningpointsoftheancientworld.c ... ics-corps/
http://www.perseus.tufts.edu/hopper/tex ... 17&force=y
https://www.livius.org/sources/content/ ... nders-army
An estimate of ancient Attica’s population is given here: - https://en.wikipedia.org/wiki/Athenian_democracy

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Re: Ancient Military Manpower

Post by Volyn » 27 Oct 2020 13:54

Steve your information brings up one of my earlier questions:
Volyn wrote:
23 Oct 2020 23:14
Does anyone know what the ratio was between combat arms and support personnel for a military force that size?
Steve wrote:
26 Oct 2020 21:27
“Alexander then carried out in person a careful review of the army that was following him. Of the infantry there were counted 12,000 Macedonians, 7,000 allies, and 5,000 mercenaries; Parmenion held command over all these. They were accompanied by 7,000 Odrysians, Triballians and Illyrians, and 1,000 archers and the "Agrianians". In all the infantry numbered 30,000".

Of the cavalry there were 1,800 Macedonians, under the command of Philotas son of Parmenion, 1,800 Thessalians, commanded by Callas son of Harpalus, a total of 600 of the other Greeks, commanded by Erygius, and 900 Thracian scouts and Paeonians, with Cassander as their commander. The total number of cavalry was 4,500.

Such was the size of the army that crossed into Asia with Alexander”.

Diodorus seems to have had a problem with addition as the cavalry total 5,100 not 4,500. There is also a problem with the infantry as 12,000 Macedonians plus the 7,000 allies and 5,000 mercenaries comes to 24,000 and they were accompanied by 7,000 from various nationalities plus 1,000 archers giving a total of 32,000 not 30,000.

Taking Diodorus’s figures at face value it seems that 37.5% of the infantry and 35% of the cavalry was Macedonian.
Based on your post can we estimate what the potential numbers of support personnel were? In WW1 the standard AEF Infantry Division in 1918 had 78.4% in combat, 14.4% in support, and 7.2% in HQ/Admin, see chart on pg. 14.
https://www.armyupress.army.mil/Portals ... h_op23.pdf

How are we to interpret the numbers Diodorus provided, does 5,100 cavalry literally mean 5,100 men + 5,100 horses and every man cares for himself and his horse, or is there some percentage of that number acting in a support capacity?

Also, who is supposed to be operating the "ox carts" for this army, would these have possibly been the Odrysians, Triballians, etc.?
Steve wrote:
26 Oct 2020 21:27
The information given in previous posts on the problems of supplying armies was informative. Given these problems it would be surprising if after starting his invasion Alexander was relying on provisions reaching him from Greece. Perhaps the Persians maintained supply depots both for their army and in case of famine which were seized and maybe the price of a city being spared was a ransom paid largely in food. As there is no mention (as far as I am aware) of Alexander looting his way across Asia maybe the treasure captured from the Persians enabled him to buy all the provisions needed from the populations passed through.
This reminded me of the Yakhchāl that the Persians built, they were used to store food as well as create ice and they were in place during Alexander's conquest, so perhaps they used these as the "supply depots".
https://en.wikipedia.org/wiki/Yakhch%C4%81l

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Re: Ancient Military Manpower

Post by Steve » 27 Oct 2020 20:14

Hello,
The web site below does provide quite a lot of detail on the organisation of Alexander’s army. For example after Phillips reforms the Macedonian army did not use ox carts or wagons.

http://turningpointsoftheancientworld.c ... ics-corps/

There is a book by Donald W Engels “Alexander the Great and the Logistics of the Macedonian Army” which seems to be well regarded. You can get an idea of the amount of supplies the army needed and how they were provided just by reading the reviews people have left of the book on Amazon. It’s £15-50 on UK eBay as of this moment in time. The book has been out a while now so may well be available in libraries.

https://www.amazon.com/gp/product/05200 ... bl_vppi_i1

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Re: Ancient Military Manpower

Post by David Thompson » 27 Oct 2020 23:35

See also the post at viewtopic.php?p=1640259#p1640259 for information on the ratio of population to warriors at various times and in various places.

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Re: Ancient Military Manpower

Post by rcocean » 20 Apr 2021 19:05

Volyn wrote:
23 Oct 2020 23:14
In an era when blades, bows and shields were the main weaponry of war, how large would a civilization's general population need to be in order to raise an army of 30,000 - 50,000 soldiers?

Does anyone know what the ratio was between combat arms and support personnel for a military force that size?
In modern societies, 19th and 20th century, ,the military population aka men between 18-45 was usually about 20% of the total. of course you had to deduct the 4-F and a small number that had to stay civilian to keep the society running. In 19th century the unfit were usually about 30%, during WW 2 it was about 15%. So to have an army of 50,000 you'd need at least 400,000 people. That's with 35% of your men needing to stay home or being unfit.

As stated upthread, the real problem before the industrial and agricultural revolutions was feeding the army. First having the food, and then getting it to the troops. Not to mention the clothing, the weapons, etc. So, that was the true limit on the size of the army, not the number of available young men.

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