Ok, here is the deal... In my story, I am trying to create a small kingdom containing somewhere 1000-1500 people with a 30-70% female to male ratio & 10-90% children to adult ratio. It is an old fashioned medieval age era and also the kingdom is underground, beneath a very huge mountain (No, they are not dwarves).

The society is divided into various stratas consisting of people from different vocations including teachers, traders, hunters, craftsman, soldiers, etc but no farmers. They would also be maintaining animals, some as livestock like cows, goats, poultry, etc and some for war like horses or elephants. They have a source of water and their food is supplied via traders, so that is taken care of. Also, money is abundant.

So my questions are (in that order)

  1. Is the scenario feasible ? Having the entire settlement underground including the animals and sustaining everyone.
  2. What are the specifics I would need to take care of while setting it up, like the area it would cover, set up of the kingdom to accommodate the residents, the local shops, the animals, the nobility, if any ? Also, need to take into account the creation of perimeter defenses, though it would not be that huge.
  3. Is the original estimate of 1000-1500 enough to maintain the kingdom or will I need to increase them ?
  4. Since the kingdom will have a small army, it naturally follows that it would need barracks to house the soldiers, armory to store the weapons, blacksmiths to make the weapons, traders who trade in the specific metals used to make the weapons...it's kind of a snowball effect.. So what are some other similar things that would be required to sustain the kingdom ?
  5. Any other general scenarios that I would need to take care of, considering that the kingdom is underground.

Any maps detailing the setup would also be welcome.

Note: was not exactly sure of which tags to apply, feel free to change them.

  • $\begingroup$ How big do you want this army to be? How big is your noble class? Neither warriors nor nobles produce, and they both consume enormous amounts of resources. Underground may be an enormous hindrance unless relying on plants that eat "underdark radiation" or similar magic. On the other hand, it decreases the need for perimeter defense resources. Is there magic? Magic can be a great enhancer for food production (standard druidy/agriculture goddess crap), metalsmithing (conventional fuel may be hard to come by underground), and other industries. $\endgroup$ Commented Nov 3, 2015 at 20:59
  • 1
    $\begingroup$ 1000-1500 really too small to constitute a Kingdom. More likely to be a clan or tribe chieftainship or a lordship (depending on development level). 10,000-15,000 more likely for a small realm. $\endgroup$ Commented Apr 22, 2020 at 15:26
  • $\begingroup$ One question at a time please! I count at least four interrogation marks in there! $\endgroup$
    – elemtilas
    Commented Apr 22, 2020 at 21:13

3 Answers 3


An underground kingdom of 1000-1500 people is plausible with a long string of provisos. A medieval group with no native agriculture capacity is going to be completely dependent on trade for food stuffs for humans and animals alike. In order to maintain a food supply, your kingdom will need to make something incredibly valuable that a very close agriculture kingdom always needs and can't source from anywhere else. The logistics of moving that much food is difficult for medieval kingdoms and therefore expensive.

You'll have to be really careful with the 1:2.33 female:male ratio. Really careful. I'm also assuming that this is a mining town since money is plentiful but there's no farming.

This question and this question may be useful to your query.

Keep in mind that 1000 to 1500 people is a tiny kingdom. Dunbar's Number is only 150 so it's possible to know absolutely everyone in the kingdom in just two hops. Everyone knows everyone here.

In terms of floor space, each person will need between 100 and 400 square feet so that's 100,000 sq/ft on the low end or 400,000 sq/ft on the generous end. Obviously this amount of space is easier to supply on the surface than underground but if the primary industry is mining then building large underground space isn't too hard. 400,000 sq/ft doesn't include offices, shops, stables, barracks, palaces, trade houses, mining facilities, foundaries, cisterns or food supplies. All these additional facilities can easily double or triple the floor area needed. For comparison, the largest structure by volume is the Boeing Everett Factory at 4.3 million sq ft.

The amount of exposed surface structures can be very small since everything else is underground. Tunneling to attack this kingdom will be slow and easily detected. But, also keep in mind that your inhabitants are highly dependent on air from the surface (unless you use magic to make breathable air) so those air vents must be heavily defended. You'll also need to be able to handle flooding and cave-ins. Handling the tailings of excavated rock/dirt will need to be handled too since pilling it up next to the kingdom's entrance is both ugly and potentially dangerous.

Why do you need a standing army? Are they defending the mine from attack as the standing security forces or is the king just a warmonger? As you said, a standing army is expensive so it either needs to justify its existence in active defense duties or it is by the personal whim of the king. (If the latter, expect a lot of griping about taxes and conditions created by bored soldiers.)

  • $\begingroup$ I'm assuming the kingdom needs a standing army to keep the neighbours who have to supply its food from just deciding to starve them out for political advantage. This is going to be a huge problem, because their farming neighbours will outnumber them by a factor of at least 10 (assuming usual mediaeval farming efficiency). $\endgroup$
    – Mike L.
    Commented Nov 3, 2015 at 21:35
  • 1
    $\begingroup$ @MikeL. This sounds more and more like a highly lucrative gold/silver/platinum operation in the same vein (ha!) as the corporate towns run by the coal companies in West Virginia USA. $\endgroup$
    – Green
    Commented Nov 3, 2015 at 21:39
  • $\begingroup$ West Virginia is quite far removed from the middle ages. Keep in mind that US of the time didn't have to rely on food imports and these towns were making money that was guaranteed by the federal government as the legal tender. No such guarantees here. $\endgroup$
    – Mike L.
    Commented Nov 3, 2015 at 21:52
  • $\begingroup$ The greater business/political environment of WV is very different than medieval Europe but in terms of small communities dedicated to one industry, I think there's plenty of similarities. $\endgroup$
    – Green
    Commented Nov 3, 2015 at 22:00

TL;DR: It's not a stable situation.


I am going to completely forgo any technical issues with actually constructing the underground kingdom; let's just assume that space, illumination, ventilation and such are taken care of without compromising defensibility.

Since we are talking about mediaeval technology however, the weak point is going to be food (both for the people and fodder for animals). There is a reason why wealth in the middle ages was measured not in coin, but in land; you can't eat gold, but you can grow food on land.

Generally anything between 90-99% of the population of a self-sufficient kingdom would have been employed in agriculture just to keep everyone else from starving, and even then famine was a semi-regular ocurrence.

So, your kingdom (and at a 1000 people, it's a tiny one) has a big problem - it's surrounded by at least ten times their number in farmers, and it needs to play nice with all of them to avoid a catastrophe. It won't have much of an army, either.

Political implications

Obviously, even if the kingdom were completely impenetrable to siege or assault, all an attacker needs to do to utterly ruin it is to stop food supplies going in.

In the middle ages, this problem was generally solved in one of three ways:

First was that the city would be endowed with farmland (and the associated villages) as a part of its founding charter. This would effectively make the city self-sufficient and the farmlands part of its polity.

The second one was often used for mining towns; these would be owned by the Crown, which meant that cooperation of their food suppliers was guaranteed by the implicit threat of the overwhelming strength of the royal army.

The final one was a hallmark of ancient city states; they would just form an army, go on a campaign and conquer some farmlands to feed the city, repeating the process as needed as the city grows.

Obviously all three of them are incompatible with your premise of sovereignty of the city-kingdom not extending beyond the mountain it is under. If you consider its history, it would be pretty difficult to explain away how there never was any conflict between the city and the surrounding kingdoms, which would have ended either in the destruction of the city, or by conquest of the surrounding countryside.

Solution: Either give the kingdom some farmland (which will then have to be defended), or make it so that both the kingdom and its neighbours owe fealty to a powerful emperor-type figure which acts as a patron and by force of arms prevents outright warfare.

Population and army

The rule of thumb is that in a mediaeval population, about 15% of the people are useful as soldiers. With the ratios you are presenting, it will be maybe twice that, so let's call it 500 soldiers. This is about the size of a battalion; if it comes to blows with the neighbours, you can expect them to field about nine times that (assuming a ratio of 95%, ie. a population of 30k). Since your city is already screwed if it comes down to a siege, you need to meet them in the field; which in turn means you need some ace up your sleeve that you can reuse and the neighbours can't replicate.

Otherwise the composition can be basically whatever you want it to be, since you did away with farmers; I'd expect about one noble family, or a couple of patrician families that are also traders or some such; majority of the "lower" and "lower-middle" class occupied with mining and associated crafts (if mining is the primary economic activity) and the rest of the middle class doing the teaching, trading and high added value crafts.

The population is altogether pretty small, though; don't expect to be seriously developing more than one industry.

  • $\begingroup$ Here is another way of aquiring food : The mountain over the city could be the only passage through a natural obstacle (moutain range, impractical swamp, desert, etc), eased by the work of this kingdom, which would then demand a toll for safe passage. This toll would be in the form of food supplies $\endgroup$
    – Axel B
    Commented Jul 13, 2023 at 15:55

I doubt it, medieval societies simply don't have the tech for it.

The first and most obvious challenge is the lack of light. Humans need sunlight for vitamin D production, as well as for mental health reasons. Torches can be use but the smoke will be very unhealthy.

Maintaining the mine with medieval tech, preventing caveings, making sure that the mine is properly ventilated, etc, will be virtually impossible.

Finally, not having any food production makes the kingdom extremely vulnerable. How long before the neighbouring kingdoms decide to starve them out and take the extremely profitable mine?

  • 1
    $\begingroup$ "Maintaining the mine with medieval tech [...] will be virtually impossible." I have to disagree. People did in fact operate and maintain mines not just in middle ages, but going back to ancient era as well. You just can't expect to have a Kazad Dum. $\endgroup$
    – Mike L.
    Commented Nov 4, 2015 at 20:56

Not the answer you're looking for? Browse other questions tagged .