Population Size and Army

[Devor]

I'm trying to figure out the question of population size and the corresponding armies for my WIP. In my notes, I've assumed that the entire region can field a total of 100,000 soldiers, making it easy to gauge their relative strengths and sizes. But now I need more of an answer than an estimate.

How many people do you need to field an army of 100,000?

 

[Lawfire]

I would assume it depends on the quality of soldiers. Are they militia of various ages, or are they all well trained regulars?

 

[Chilari]

Well, it depends on how militarised your country is. If it's at war there will be more poeple in the army thatn in peacetime. If that was threatens the country itself, or neighbouring allies with a real threat that they might be next if the ally falls, it'll much higher still, and even higher again if conscription is in place.

For example, the British Armed forces. Let's look at some numbers (active personnel only):

Now:
British population: 62,262,000
British Armed Forces: 227,160
Proportion of population on active military duty: 0.36%

During WWII (1940), with conscription for men aged 20-23 only:
British population: 48,220,000
British Armed Forces: 1,650,000
Proportion of population on active military duty: 3.4%

During WWI (1916) with no conscription:
British population: 39,294,700
British Armed Forces: 2,600,000
Proportion of population on active military duty: 6.6%

So yeah, it depends on the military situation. It might be as low as 2 million or as high as 25 million.

 

[Saigonnus]

Don't forget if you are having some large army in the field it needs to be moderately well supplied via supply trains. It is probably bordering on the impossible to have them feed off the land as it were; gathering supplies as they go, though certainly they could supplement what they get from the supply trains with things they come across. Napoleon often had his soldiers forcibly "commandeer" supplies from towns and villages they came across, often leaving very little for the locals to live off of, so it really depends on the leadership and "alignment" of the army what you should consider as options for feeding the army.

Also consider the basic needs of the soldiers, shelter, clothes, equipment, weapons and armor for the different types of soldiers in your army. Even if it is never mentioned in the story, the disposition of the army is something you should know inside and out and of course a basic knowledge of military tactics can't hurt either. Generally I write out a hierarchy of the army, how they are divided into units, the types of soldiers in the units and what those soldier wear and use in combat.

Generally speaking, most medieval battles were fought between forces in the hundreds or thousands rather than tens or hundreds of thousands, those kinds of battles are somewhat rare in real word history since until the 18th and 19 century the population of most European countries were fairly spread out and the local lords are the ones who gathered "conscripts" when the king demanded it of them.

 

[Devor]

Generally speaking, most medieval battles were fought between forces in the hundreds or thousands rather than tens or hundreds of thousands, those kinds of battles are somewhat rare in real word history since until the 18th and 19 century the population of most European countries were fairly spread out and the local lords are the ones who gathered "conscripts" when the king demanded it of them.

This only makes it more difficult to answer, but I'm not writing in Europe. The population is centered in - I guess you could say small city-states, based on where the water is. So you would see a heavily cultivated region, maybe 10 square miles, surrounded by a large span of nothing.

So it would be a lot easier to raise an army on the spot since you don't have to cull through so much of the countryside.

 

[Caged Maiden]

My dad once told me it took 50 peasants to support one armored mounted knight. I use that general ratio when I consider my military might in my stories. There's a lot of support that goes into soldiers, and depending on whether it's a good year or bad year, or weather conditions, crop yields, etc. it probably varies widely. Where one year your men are well-fed, the next they may be starving in the field and turn to pillaging to survive.

 

[Devor]

My dad once told me it took 50 peasants to support one armored mounted knight. I use that general ratio when I consider my military might in my stories. There's a lot of support that goes into soldiers, and depending on whether it's a good year or bad year, or weather conditions, crop yields, etc. it probably varies widely. Where one year your men are well-fed, the next they may be starving in the field and turn to pillaging to survive.

That's a good point. But it would be a different number for armies that fight at home and disband quickly - something that might happen a lot in this story.

That also raises the question - how long does it take to rally an army? Are there tricks you can use to speed that process up?

I'm dealing with a few regions, but only one is the aggressor and the others are mostly raising troops for self-defense. The location I'm working on right now currently has a few thousand standing soldiers, a group of a few hundred let's-call-them knights, and merchant guards compressed into service. They're refusing to raise the militia, and I also need to know at what point that becomes too late. And I'm trying to get an idea of how the actual numbers look so I can adjust the bad guys accordingly.

 

[Caged Maiden]

many "soldiers" were peasants. They were taken out of the fields and sent to the army as it was every lord's job to fill his liege's ranks when called upon to do so.

 

[Graylorne]

I'd say the mustering speed of your army depends first on your lines of communication. How do you muster your soldiers? Do you have te send runners to every household, to the town elder or the local lord? Or signal fires, semaphore towers, smoke signals, carrier pigeons? Do you have garrisons that can march in only hours or do you have to gather the men from the fields, arm them, etc. in 48hrs. How is the state of your roads? (Or do they go by water.) Is there a tradition of mustering, so that everybody knows what to do/where to go? Able officers or local yokels?

Is it only for local defence, it could be fairly quick (depending on how large an area 'local' is.) For an attack days away you have to arrange a commissariat (food, drinks, tents, weaponry, horses, carts & bullocks).

Concerning the size of your army compared to the population I found this (fictitious) example, perhaps it could give you an idea:
Keeping Your Fantasy Armies a Little Less Fantastic

 

[Sheilawisz]

I think that at least 1% of the population of a Fantasy country could be composed by professional soldiers, and if you include other professions that would be called to arms, then it could be some 5% or more in cases of extreme need of troops for war.

 

[Sheilawisz]

That sounds pretty reasonable and plausible, Devor =)

 

[Devor]

That sounds pretty reasonable and plausible, Devor =)

And I just deleted it because I kept changing the numbers.

I think they were:

.05% standing
+2% for war
+3% for self-defense

 

[ThinkerX]

That also raises the question - how long does it take to rally an army? Are there tricks you can use to speed that process up?

There is one, which if my somewhat hazy memory serves, was used by the Roman Empire...at times. It was also used in the old USSR and elsewhere:

Essentially, the regular army is 'over officered', with double the number of offers and non-commissioned officers actually needed for each unit. In times of crisis (full mobilization), these 'extra' officers and NCO's are split from the regular units to form the core of 'Twin' or 'Gemini' units. Hence, peasants straight from the field have competent officers and NCO's who actually know what they are doing (how to train them properly and quickly).

I used this concept for my own world: normally the Solarian Empire has a dozen legions, but in the event of full mobilization, each legion is 'twinned', with the new legion being trained up as much as possible enroute.

I also adopted the imperial roman model for supplies: a percentage of the crops goes straight to the military, and each soldier, as part of his kit, lugs around enough supplies to last a couple of weeks. 'Twinning' the legions, though, would eat into the food reserves in a hurry.

 

[Robert Donnell]

The USA fielded 6.5 % of our Population in WWII, The Germans fielded 30% but used slave laborers extensively and Denmark provided 30% of the food Germany needed. So 30% is too high, so I would guess 20% is about the maximum so to field an Army of 100,000 you would need a prewar population of at least 500,000. If your prewar population was 100,000, then 20,000 is about the most you could field.

 

[ALB2012]

Personally I cheated. I have the Witch-Hunters as the dominate military force, run from as yet to be specified location via forts dotted about the land. As having a son in the Order is prestige ( So far it is just men, they are quite conservative in their outlook) then often the nobles and well to do send their sons there. In theory they can conscript as an when they chose as they are the law and the army. Often it is a better life than being a peasant or poor in the city. Most people would dare not refuse. Often they have a unit of a few men, after all one lone mage alone cannot possibly take out all of them, especially a young untrained one.

They have larger squads available for when needed, their are more threats than just mages and the commanders who basically run a region can call on other forts if they need extra. They are supported by the slavers to whom they turn a blind eye so long as they get a cut and the nobles who support the regime. I have a battle in book 2 but I never state precise numbers. The leader is a commander so he is pretty important and has the sway to call in back up if they are going after someone nasty.

They peasants support them but the Witch-Hunters have the lands around the forts to help with food, often with a puppet lord.

 

[Struddles]

It could also be depending on the civilization. In what I'm writing the main society is a militaristic society like that of the Spartans. Every person is required to enlist into the military and they actually are not only strong military wise but they are bent on keeping peace between countries. In being an entirely military focused people they actually have a strong relationship with a neighboring nation that they provide protection for in return for resources. Since the other nation is extremely weak militarily it balances out and one cannot live without the other.

This does not only make one country extremely strong in one aspect but balances it out in other aspects.

A fantastic example of what I'm talking about used in a great series of books is The Hunger Games. Where each district supplies to the main city not only do they supply weapons, troops, food and vital resources to the capitol in itself is quite weak without the district allowing for a balance and a sense of vulnerability in an area.

 

[Robert Donnell]

Well if you looked at France in 1939, they mobilized too well, men that were needed at home were drafted so quick that Trains and factories were idled just when they were need most because all of the trained men were in uniform, this took weeks to straighten out.

No matter how militaristic you are 20% is about it, the 30% for Nazi Germany was a total number across the war years, not all at once until the bitter end when old men and boys were gang pressed in the VolksSturm.

 

[Chilari]

Struddles: bear in mind that while the Spartan citizens were primarily military, they did not manage to do that unsupported. Aside from the citizens, there were also the Perioikoi, the non-citizen freemen living in Spartan territory (and since citizenship was based on owning enough land to contribute food to the common messes in Sparta, this was probably quite a large chunk of the landowning population) who owned or rented land and thereby supported the citizen army. Then there were the Helots, slaves who worked quite a lot of the land and were required to serve as baggage carriers to Spartan citizens when they went to war (I believe to the ratio of 7 helots to one Spartan). So Sparta might be a highly militaristic state, but it didn't do that without two vast underclasses: one free, one enslaved. The citizens of Sparta were the elites, and they were essentially professional soldiers. The majority of the population of Sparta were farmers.

 

[Struddles]

I've completely kept that in mind and managed to design something around that. Where the main characters nation is a militaristic city but there is a massively supporting race that does take a major role throughout my entire book. I realized that I did want a society that's was militaristic and by doing so I knew that there had to be give somewhere. So the biggest offset for me was that since the main nation in my book was so highly focused on their military strength that they relied almost exculsively on a society that does not require nearly as many resources to be able to flourish. One lacks military while the other lacks resources. To me it was a perfect fit. Though it is definitely up for change especially with feedback from the forum family and friends.

 

[ThinkerX]

I've completely kept that in mind and managed to design something around that. Where the main characters nation is a militaristic city but there is a massively supporting race that does take a major role throughout my entire book. I realized that I did want a society that's was militaristic and by doing so I knew that there had to be give somewhere. So the biggest offset for me was that since the main nation in my book was so highly focused on their military strength that they relied almost exculsively on a society that does not require nearly as many resources to be able to flourish. One lacks military while the other lacks resources. To me it was a perfect fit. Though it is definitely up for change especially with feedback from the forum family and friends.

Thing is, barring something really unusual, your militant city would have almost certainly conquered the not so militant city. To the military mindset 'alliance' wouldn't be enough.

'Keeping the peace' is also unusual for a militant society.