Hello guys,
This question might have been answered before but the answers I read so far didn't satisfied me. My questions comes from the sheer size fo armies during middle ages compared to classical, hellenistic, and late antiquity. I know that governance system relly more on feudal levies than state controlled armies, so this obviously had an impact over the size of armies.
Still it amazes me,how a city like rome during the punic wars could gather a 40.000 size army, being beaten, recruit another one, and beat Cartago; but for the Third Cruzades Three Kings ( who happened to control close to 70% of western europe's landmass) couldn't gahter the same amount of people.
So even if afeudal system explains part of the size difference, it's an incomplete explanation. From what I read Byzantines during the X century could have a tagmata force around 15.000 men, this trembles to the size of the armies of diadiochs, or roman republic , or even some greek cities, even though we know Byzantine Empire did not relly on feudal levies.
It's also worth noticing the huge size of barbarians armies some roman generals, incluidng Julius Caesar, noted. I know their stimates are more likely an exageration, still that a man who had several legions under his command like Julius Caesar was amazed by the size of the armies that gauls could muster, means something. How come some tribal lords could gather more men than a middle ages KIng who had a broader state aparatus than any tribal leader could ever had?
The only suitable explanation for me, is that the armies wer smaller because the recruiting pool was smaller. The question is how much? Is there any demographic chart that compares medieval population vs antiquity population? How much was the difference? Are there any other explanations we can think?
You might want to take a look at some of the previous discussions of the topic here on AH while you wait for an answer. In the meantime, I'll throw in a couple comments I think are worth keeping in mind.
Right off the bat, the evidence suggests it at least wasn't a lack of population in medieval times that restricted the size of armies. England in the 14th century had a population of similar dimensions to the Roman Republic; France had a population on par with the Seleukid empire. When you compare the size of armies to their share of population, England and France come in under 1%, while the Romans peak at 5%, and smaller states like Makedon and individual Greek cities could do 10%+. I looked at a couple other demographic factors -population density, urbanization- but they don't really seem to correspond to the degree of difference.
Generally speaking, the city states and tribal cantons of antiquity relied far more on a universal obligation to fight than did medieval kingdoms. Not just citizens, but quasi serfs and even slaves would fight, depending on the circumstances. By contrast, medieval kingdoms like France and England, especially in the Hundred Years War, relied on contractual recruitment. The king would contract with prospective captains to provide X troops for Y pay over Z days.
It should be fairly plain that calling up all men able to bear arms results in a larger army, so the question there is why medieval kingdoms didn't do this. This is a question I'm not sure I'm completely able to answer. However, I do think I've seen enough data to raise some potentially interesting points of discussion; I have an ongoing project where I look at how well states across different periods are able to translate population into money into armies, so a lot of demography, numismatics, and muster rolls.
It seems that France and England in the 14th century both levied far lower taxes per capita on their subjects; about 3-4 grams of silver per person per day seems to be a rough range. The Romans of the Mid Republic however demanded about 10 grams, and this was on the low side for ancient states of the period. To contextualize these figures, I try to look for wheat prices as a rough cost of living index; at the same time medieval states are collecting less precious metal than the Romans, prices have gone up. A gram of silver in Roman times could get you roughly 4.85 liters of wheat, but in 14th century England, it's more like 3.2 liters, so if you look at per capita tax rates in terms of their purchasing power, the Romans were collecting four times as much wealth per person. At the same time, they paid soldiers much lower wages than medieval states (1.35 grams of silver a day for a Roman foot soldier vs 2.7 for an English equivalent), so this greater wealth goes further. The difference becomes more marked when you get into elite troops; while Roman cavalry drew three times the pay of the infantry, an English man at arms was typically entitled to almost six times the wage of a common foot soldier.
When you draw up projections of what the finances of ancient and medieval states could manage, there's a striking difference. The Seleukids could afford to pay 333,333 infantrymens' wages for 180 days based on their 3rd century BC revenue, while England could only manage about 37,000. But wait, there's a twist! When you look at the forces they actually did mobilize, the Seleukids only mustered 42% of this total (in monetary terms; the headcount was less, but balanced by the presence of more elite and expensive troops), while the English maintained an army on campaign that came out to 212% of what they were able to pay. French finances tell a similar story, even more extreme; their army in the 1340 campaign represented roughly 3.42 years of revenue. The Romans seem unique among ancient states in breaking the 100% threshold, with a peak mobilization of about 120% of their annual revenue.
In general, it seems medieval states were, compared to ancient states, bad at turning population into money, but quite good at turning money into armies. Why this was is something I still don't know, though. Medieval kings had to contend with a more powerful nobility; Rome was run by a class of wealthy landowners, but as a corporate body of citizens, not as a confederation of princes with their own military resources. On the other hand, royal ideology in the Middle Ages was far more open to the use of credit than in the Ancient world, where debt was seen as a means of subordination.
TL;DR who fucking knows