View Full Version : How much space does an army take? What about size/numbers?

2015-10-07, 06:23 AM
Hi there.
IMC, we will need to start using armies (not for tactical combat) for our story.
I'd need some help visualizing the right number of people for an army.

I hear a medieval sized army would be 2,000 to 10,000 people average.
Does anyone have photos of that numbers of people? I can't visualize the difference between 2,000 and 10,000 really.

For example, this common image:
How many orcs would those be, roughly?

How many people would you need do occupy a city after you defeat its army?

How many people can a galleon carry? What about if they are all undead and need no living space and can be stacked very tight?

I am just looking for approximate numbers, in order to be believable.

2015-10-07, 07:28 AM
If I recall from the special features of the LotR movies, the special effects guys said that Saruman's horde of uruks numbered about 12,000. That is, by the way, a modest-sized outdoor rock venue in modern terms, about what you could fit in a medium-sized park.

As for occupying the city - do you mean just looting and pillaging and keeping the population oppressed, or do you need to actually establish a military government, keep the sewers running and haul the garbage away, run a judicial system, and everything else that goes with running a city? Because you need a much bigger force for the second one, and more to the point, you need a much better trained force. Conscripts, scruffy mercenaries, and barbarian warriors can do the first, but you'll need a professional peacekeeping force to do the latter.

"Galleon" is, unfortunately, a very broad term. It generally refers to any narrow-hulled, square-rigged war ship with a high forecastle and multiple gun decks. Depending on how big it was, and whether it was built for ship-to-ship combat or for troop transport, you could fit anywhere from 100 to 600 combat troops on one, in addition to the complement of sailors and support staff. (Note that, if you are using them to transport cavalry, one horse takes up approximately the space of 5 soldiers.)

If they are undead, and therefore don't need food, air, exercise, or sleeping space, you could probably fit five or six times that, just stacking them like cordwood in the bottom of the ship.

2015-10-07, 07:35 AM
Thanks, that is very informative!
I will put that information to good use

(And by the way, taking a city was intended as the first case, oppress the city long enough to enstabilish a small base without incidents or people taking arms and trying to fight, also having the capacity of killing or routing everyone if needed in order to secure the land)

mig el pig
2015-10-07, 08:40 AM

On the left you have around 2000 cavalry, on the right side you've got about 1300 infantry.

On your question about occupying a city. It depends on a lot of factors. A lot of castles could easily be defended for months by less then 100 men. So to occupy a city that has a keep you don't need much more then that.*
The risk of an uprising is severly limited due to how well protected you are. They might rebel but if they can't take the castle before a relieve force arrives they are in for a world of hurt. War is harsh, especially for those who tried to rebel (and probably broke a few oaths of fealthy in the process)

* Presuming you're not activly trying to run everything in the city.

Something to consider is that Medieval battlefields were not very big.


the Flemish (black) force is about 8000 infantry, The french force is about 2500 mounted soldiers and 5000+ infantry. The battlefield itself is just a bit over 1kmē

The same at Hastings. Roughly 8000 men on both sides and the battlefield itself isn't much bigger then 1,2 kmē

Lvl 2 Expert
2015-10-08, 06:18 AM
What I do for imagining the space people take up is putting numbers on things. If an army of 10.000 marches along a single road the men will all have about a single square meter (or yard, for estimation prposes those are the same thing) to their own. Let's say they march in lines of six, because more didn't fit on the road, that means that a one hundred person company takes up about 17 meters (again, or yards) of road (about the length one fully grown tree that fell over in the latest storm) and the whole army would take up a 1.7 kilometers (one mile) stretch. When you're standing on a flat bit of earth the horizon is about 5 kilometers (3 miles) away, so the front soldiers could still look back and easily see the ground the last people where walking on, if there weren't 10,000 soldiers in the way. Since people walk at approximately 5 kilometers an hour (so yes, it takes about an hour to walk to the horizon) the soldiers in the back will have to march for about 20 minutes in order to get to where the first line is right now. If an officer in the back sets his horse into a gallop at a bit over 30 km/h (20 miles/h, 10 m/s, the speed a horse can keep up for about an hour, and also the top speed of a human sprinting) it will cover that distance in a little over 3 minutes.

Now for on the battlefield. Let's say they build pike squares (I don't know enough about medieval warfare, so I'm just assuming similarities with certain later forces here) of 500 men. How big are those? They're probably closer packed than marching soldiers, with having to form a good pike wall and stuff, let's assume every soldier now has only 75 by 75 centimeter to stand on (75 centimeters is 2.5 foot or the length of a normal step). The root of 500 is about 22. So the square formation we're imagining here measures 22*0.75 by 22*0.75 = 17 by 17 meters, 50 by 50 foot. A ten thousand person army consisting entirely of pike squares consists of 20 of those. If they're spaced in the classic roman checkerboard pattern that looked so cool in Spartacus this means the whole formation could measure 170 by 70 meters [EDIT: I put 170 by 140 meters here, but that was a mistake.], half of which is empty space. That's a size comparable to that of a pretty small block of houses, or a decent modern ship.

Cavalry takes up more space. D&D makes a horse take up 4 times the space of a person being a large creature. In reality it's probably a bigger difference than that because horse formations are probably not quite as tight. Having no experience with the beats, I'd expect one to take up about 2*4 meters of battlefield. 1,000 riders might take up a area of 100 meters wide (50 horses) by 80 meters deep (20 horses), a third of the space ten times their numbers in foot soldiers are using, even with the checkerboard pattern.

As for the differences between different sizes, just take those numbers and fold them around a bit. A force 4 times as small takes up 2*2 less space.

As for the sizes of the armies, another nice case study may be the Battle of Worringen (https://en.wikipedia.org/wiki/Battle_of_Worringen), part of the Limburg Succession War (https://en.wikipedia.org/wiki/War_of_the_Limburg_Succession). It's a pretty typical conflict over the future of one of the many city states/duchies that existed in Europa at that time. (Even though Wikipedia claims it's one of the larger battles in medieval Europa, so I guess it may have gotten out of hand a little bit.) Numbers wise the battle was 2,300 armored cavalry and 2,500 foot soldiers (of which apparently only 40 died? Are we sure they even counted dead foot soldiers in those days?) vs 2,800 armored cavalry and 1,400 men on foot (1,100 died on that side, over a quarter of their forces.) Apparently high numbers of cavalry were not uncommon as long as the warring parties were mostly upper class folks with their official armies, instead of say a peasant revolt. The map on that Wikipedia page says the battlefield was about 1 by 1.5 kilometers.

As a side note on the ship thing: soldiers were already packed pretty tight. Sure, if you can literally stack your undead like boxes you'll fit in a lot more, but soldiers already were a lot like cargo. They typically couldn't go on deck, and they didn't have much more space than say slaves would have (although their rations, clothing etc would have made their lives more comfortable by a fair bit, they were only dying a little bit.)

2015-10-08, 05:51 PM
Do you mean the entire army, or just the combatants when deployed in battle order?

Camp followers in certain cultures and certain periods of history could double the size of the fighting roster.

2015-10-08, 11:59 PM
Short answer: As much space and as big or small as you want.

Long Answer: It varies according to the forces at play. Sure. You might have giant marching forces of several thousand men at a time. This could absolutely happen. But this was also when you had the forces of empires marching against each other.

If Duke Bearington who lords over a village, gets together with a few friends and marches on his rival Duke Guy five leagues over, they would still have an army, but it would probably number only in the hundreds.

And you're probably not getting past around the 10-12,000 mark unless you have gigantic, continent sprawling empires marching against other empires.

Brother Oni
2015-10-09, 02:07 AM
And you're probably not getting past around the 10-12,000 mark unless you have gigantic, continent sprawling empires marching against other empires.

Depends on the culture. During the Japanese Sengoku civil war, the deciding battle of the war (Sekigahara) had in excess of 80,000 soldiers on each side.

Battles during the Chinese Three Kingdoms era often had in excess of 100,000 soldiers (supposedly Wei forces were 200,000 strong, while the Shu army was 100,000 at the Battle of Wuzhang Plains, but I'd take those figures under advisement).

At the start of the Mongol's rise to power with their conquest of the Jin Dynasty, they were supposed to have over 104,000 soldiers at the Siege of Kaifeng.

2015-10-10, 09:25 AM
And you're probably not getting past around the 10-12,000 mark unless you have gigantic, continent sprawling empires marching against other empires.

In the Roman and Hellenistic eras, 25,000 men was a pretty routine size of army for powerful states that weren't sprawling empires. That was deemed the "best" size of an army in terms of being both effective and not too big to keep supplied for long periods of time in hostile territory.

In shorter periods of time, it wasn't unusual for armies of 100,000 men to be brought together.

Also bear in mind even before the days of the Prinicipate and control of much of the Mediterranean, Rome could furnish multiple armies of 25,000 men (which was the force a consular/pro-consular general would have at their disposal). During the civil wars, there were regularly clashes between hundreds of thousands of men.

2015-10-10, 04:51 PM
Keep in mind that most soldiers on a battlefield don't die, or you'd never sustain those numbers over multiple years of war. Even a drawn-out battle will see three-quarters of the losing soldiers alive at the end. Occasionally, it's much worse, but that's usually intentional slaughter, it's not required to win the battle.

Bulldog Psion
2015-10-10, 05:03 PM
Army size really depends on logistics. Medieval armies were fairly small because their logistics were rather shaky; the ancients, with superior logistics, could muster considerably larger forces.

So, it really depends on how good the roads are, how good the bureaucracy is, how scientifically the quartermaster corps works, and how much money is available to keep all this running.

If the medievals had Roman levels of logistics, armies of 80,000 or 100,000 would likely have been fielded. There might have been 80,000 Hungarians and allies versus 70,000 Mongols at Mohi in 1241. The Mongols frequently fielded gigantic forces -- see again, superior logistics.

2015-10-10, 05:25 PM
Most soldiers don't die in battle. Casualties will be very high in long wars.

On the other hand, long wars were rare in the medieval period because levies had to go home for the harvest.

Quite often, the whole army won't actually make it to the battlefield. Armies tend to split up to march and come together for battles and don't always manage to entirely come together. Other times soldiers from different parts of the country who mean to form a single army will be forced into combat before they can do so.

If a fantasy army has stuff like ogres and bound monsters in it, human troop numbers from the real world are a bad comparison.

the Japanese Sengoku civil war, the deciding battle of the war (Sekigahara) had in excess of 80,000 soldiers on each side.

Sekigahara wasn't even a important decisive battle. Its mainly due to other events that it ended up being the last battle of the period in happen-stance. The most important battles aren't always the biggest ones.

The Japanese invasions of Korea in the same period both had over 140,000 soldiers.

The Mongols frequently fielded gigantic forces -- see again, superior logistics.

The Mongols were usually outnumbered. The Logistics of the steppes can't be compared to the logistical challenges of other terrain types so calling them 'superior' is meaningless. Unless you're talking about the Yuan Dynasty Mongols who mostly used traditional Chinese style armies and fought outside of the steppe.

Logistical superiority isn't always what it appears. The armies of Napoleonic France generally relied on foraging but were functionally superior to the more bureaucratic German armies with their complicated baggage trains and supply systems.