From Land to Subsistence | cities, population, subsistence and land area

Table of Contents: The organization here is top down, or from macroeconomics to microeconomics. You could do it the other way around, but you could very likely end up with some very unexpected (and perhaps unrealistic) results. Best way to go about this is to decide on some calibration society/city from which the other societies will be derived.

KINGDOMS | Total population | Cities, city types, urban population | City size | How many cities? | Army size and national power

TOWNS | Margin of living | Rural area vs. population | Rural edge 

VILLAGES AND MANORS | Food | Crops | Crops and society | Animals | Land division | Taxes


Total population: The total population of nations depends on a number of factors, some of which
are discussed in the following sections.

POPUL = AREA * (1-WILD/100) * (1-WASTE/100) * YIELD * DENSITY * (1+URBAN/100)

POPUL = total population
AREA = total land area
WILD = uninhabited land as % of total: 20% is small, 40% is normal, 60% is big
WASTE = on inhabited land, land unusable for agriculture, (march, mountains, desert) as % of total: 10% is small, 20% is normal, 40% is big
COAST = length of coast: for purposes of food production, each mile (or km) of coast is assumed to equal 10 squaremiles (or squarekm) of land due to fishing. Of course, the length of the coastline should be calculated in reasonable scale, say in 20 mile steps.
YIELD = relative yield acquired from the land: 1.0 is normal, 0.5 is poor and 1.5 is great. Yield depends on a number of factors: crop, land quality, agricultural techniques and climate. Of these, the three first tend to stay relatively constant over a short time period, but climate may vary a lot from year to year.
DENSITY = reference population density per squaremile or squarekm in reference situation: no wasteland, no uninhabited land, yield=1. Density depends on the subsistance type of the culture. You can also figure the effect of technology and crop cycles in here. 

Subsistence density sqmil density sqkm
Nomad  5 2
Seminomad  10 4
Semisedentary  50  20
Sedentary  100  40
Industrial  more  more

Here are some population densities (actual average densities, _not_reference densities):
Arctic: 0.3 / sqmil
Kalahari desert: 1 / sqmil
Canadian praries: 2 / sqmil
Medieval England: 30 / sqmil
Modern Estonia: 88 / sqmil
Modern Hungary: 280 / sqmil
Modern Bangladesh: 2400 / sqmil

I've seen suggestions that hunter-collectors must keep their population below about 2/sqmil or run into environmental degradation problems. URBAN = extra people, ie. specialists, leaders and urban population, living from the surplus of the rural population as a percentage. This depends on the margin of living, but typically not directly, as leaders and other specialists will - for reasons that I won't go deeper to - more food (ie. resources) to sustain themselves than rural people. Of course, their work is valuable in increasing the extracted crop yield. Anyway, here are some figures you can use:

Tech level urban population
Nomadic 0%
Early Farming 5%
Standard Farming 10%
Pre-Industrial Farming 15%
Early Industrial 20%
Standard Industrial 30%

Here are some estimated RW urban percentages (urban/total population):
14th century England: 2% urban
14th century Italy: 10% urban (maximum for medieval Europe)
17th century Japan: <20% urban (with intensive rice cultivation)
Modern Kenya: 30% urban
Modern Argentina: 80% urban

Of course, there might be some over- or underpopulation. In that case, just multiply the population by some figure that is close to 1. 

Cities, city types, urban population: Cities are centers of urban activity. The size of urban population in a society depends primarily on the margin of living the farmers can produce. Not alone on that, however, since a large part of the non-farmers will live on the countryside. At least if they cannot operate from cities. One operates where ones customers are...

There are different kinds of (parts of) cities in terms of their function:
The RESIDENTIAL: primarily residences with few non-residential buildings. This is the best scale to use for villages and townships.
The INCORPORATED: this should be used for cities with an even mix of residences, open area and other structures.
The URBANIZED: this should be used for those cities where large areas are reserved for wharves, government structures, or other non-residential structures.
The COMMERCIAL: should be reserved for the extreme commercial cities.

City size: These are guidelines for calculating the land area required by a city (the actual city, not taking into account the rural land). A reasonable equation might be: CITY AREA = exp( ( AR*ln(POP) - 7*ln(POP_STD) ) / 9) * AREA_STD

where AREA_STD and POP_STD are calibrative figures from your "standard" city and POP is the city population. Try setting POP_STD to 10000 and AREA_STD to 22 sqmil (or 56 sqkm) by default. A simplified form of the equation would then be: CITY AREA = 0.0168 sqmil * exp( AR/9*ln(POP)) =~ exp(...)/60 sqmil = 0.0434 sqkm * exp( AR/9*ln(POP)) =~ exp(...)/23 sqkm

The AR parameter is the area requirement of the particular city type: 6 for residential, 7 for incorporated, 8 for unbanized and 8.5 for commercial.

How many cities?: Here are guidelines to calculate the number of different sized cities in a nation. First, you have to estimate the size of urban population, which is based on margin of living, and the maximum city size, which is based on the rural edge, the distance one can travel in one day using a wagon or a ship. The latter can be ignored if all food needed by a city need not be produced within one day of travel from the city.

Now, there's a handy rule of thumb for the sizes of cities. The second largest city is half of the size of the first. The third largest is one third of the first, and the fourth largest is one fourth of the size of the biggest city. And so forth. So what you really have to do is to estimate the size of the biggest city. Start from x = 1000 and calculate x*(log10(x) - 3). If this is less than your total urban population, add some appropriate figure, for example 1000 or 10000, to x: x = x+1000 until you hit the total urban population. That is the size of the biggest city and you can easily calculate the size and number of smaller cities from that. If the size of the biggest city happens to be bigger than the maximum city size, you can divide the nation into parts, each of which has one its own "biggest city".

Army size and national power: This section is mostly quite out of the hat, but may be useful if you like to
roll dice. First some definitions: rand = a random number between [0.75 .. 1.25] ((75+D100/2)/100 if using dice) D16 = D6 + D6(if the first roll was 6) + D6(if the second roll was 6) The probabilities are something like 16.7% for 1..5, 2.8% for 7..11, 0.4% for 13..16 and 0% for 6 and 12.

There are no good guidelines to really estimate army size, but this can give some rough estimate. First set these variables: MILITARY% = the percent of military personnel of population (default = D16 *
TL(military)) MILITIA% = the percent of possible militia in a population (default D16+D16-2
* TL(militia)) where TL(military) and TL(militia) are got from the table below:

TL  military  militia
Always nomadic 0 2.0
Occasionally nomadic 0.5 1.5
Farming  1.0 1.0

To get the size of army simple calculate:

The military is the number of full-time soldiers available for war. The militia is the number of part-time militia that can be raised in times of war. To get the size of navy, try this:

NAVAL SHIPS = ---------- * -------- * rand



Here naval ships is the number of warships, at or below the Bireme level and the heavy ships is the number of heavy warships at or above the Trireme level. The sailors is the number of war-trained sailors, marines, etc for the fleet of the kingdom.

The following figures are derived from Powers & Perils. Gross National Income (GNI) is an indicator of the trade/tax monies available for the empire. The power is used to compare two empire. In general, if one empire is less than 2x the power of another, they are fairly equal and will deal with each other as such. As the ratio increases, the larger will be more and more likely to have it's way diplomatically with the smaller. Production:

{ POPUL*2 / 10000, if TL is (occasionally) nomadic
{ ---------------------------------, otherwise
{ 10000

Power components:


MILITARY = ---------------- + ------- + ---------------------------
1000 3000 10


Total power:



Margin of living: Margin of living is the amount of surplus food the farmers produced. A figure of 10% is about right for medieval England, 15% for Japan (according to Lee Gold in GURPS Japan). Thus a village of 100 people (in England) could support, in principle, 10 non-farmers. Or the other way around: a town of 500 non-farmer residents would need 5000 farmers to keep them alive. I suppose the 10% already takes into account the better standard of living of higher social classes. Note that towns rarely had only non-farmers and on the other not all non-farmers lived in towns, so the margin of living percentage is always bigger than the urbanization ercent.

In principle one could calculate the possible (and even actual) number of residents in a given town when given the characteristics of microeconomics in the countryside. Unfortunately we don't have any real numbers from medieval villages concerning such things. Therefore it is better to rely on macroeconomical figures which are somewhat surer.

Rural area vs. population: A simple way to calculate rural area based on population (or the other way around) is to use the thumb rule that (in medieval England) villages of 100-300 people were located 1-2 miles apart. That is about 150 people per 2 sqmiles (about 30 people per sqkm). To get the size of the rural area surrounding a given town first set the margin of living, calculate the rural population and get the area that way.

To get a little more flexibility try following:

RURAL AREA = TOTAL POP * ---------------- * --------------------------------


CROPLAND% = the percentage of the arable land. It should be based on the percentage of area that the town lies on that is and can be used for raising crops. A value of 0.25 should be pretty reasonable.
CLIMATE = a small variable you can use to modify yields based on climate. Some tropical climates can get up to x2, while arid areas will hover around 0.3 or less.
LAND QUALITY = the quality of the land in terms of average yield. The parameter is based on historical medieval yields and can be tweaked above the suggested limit if magic is a big influence. Varies between 0.7 and 1.2.
MARGIN = the margin of food produced above that needed by the food producers themselves. This is the major factor in determining the size of the rural population. Depends heavily on the technological level. Try 0.1 to 0.2 for your standard medieval campaign.
LAND PER VILLAGE = the land area that one village (or some other agricultural basic unit, like a family) uses. For example 2 sqmils for medieval England.
VILLAGE POP = the average population in one village (or one family if you use that). Use 150 by default. For rice-growing societies try using LAND/POP relation of 0.006 sqkm (or 0.0023 sqmil).

You can also do this the other way around: get the population based on the available cropland:



Rural edge: Rural edge is a figure based on the rural area. It tells how much the furthermost farmer must travel by wagon or ship to get to the town. It is important in that is should _not_ be more than a days travel! In fact: Cornelius Walford, "Fairs Past & Present: A Chapter in the History of Commerce", writing in 1883 on the history of the English fair and market, in common law: " is held reasonable that every man should have a market within one-third of a day's journey from his own home; that the day being divided into three parts, he may spend one part in going, another in returning, and the third in transacting his necessary business there." (pg 17)

If the distance from the edge is too big, a new commercial center (a subcity perhaps) will start developing in a suitable place. This is in fact what you see if you look at the distribution of bigger and smaller towns, or any other services, on maps. In special situations a city may have a rural edge which is
longer than normally allowed. Imperial Rome for example had over million inhabitants which were fed by a constant flow of imported grain from northern Africa. In modern societies with refrigerators and highways rural edge is of minor consequence.

Although usually the rural area is in circular formation around the center, in some situations one direction becomes favored over others. This might be the case when the town is in a pass or beside a major route which was there before the town (an old road or a river). The rural area may then be approximated by an ellipse. The following is the equation to calculate the distance of rural edge:

RURAL EDGE = sqrt( RURAL AREA * N / pii ),

where N is the favorability of the best direction over the worst direction (presumably perpendicular to each other). The rural edge is the direction to the best direction. The distance of rural edge to the worst direction is RURAL EDGE / N. The normal circular situation is a special case with N=1.


The basic agricultural unit in medieval times was a village. In England the villages were almost consistently 1-2 miles apart. A typical village had 100-300 residents with 4-8 members in each family on the average. Each family had a patch of their own field and access to common pasturage for animals. During other times a manor or even a single farmstead might have been the basic unit.

Food: Below I'll be using bushels (bu.) to describe an amount of food (flour, bread, meat, milk, whatever) that gives a certain unspecified subsistence to an average human being. An average human will need 24 bu. of food per year to work and survive. For children and elderly the requirement is considerably less, perhaps half as much.

For economic purposes let's say that one bu. of food equals one economic unit (eu). A food producing farmer may then sell his surplus to people who don't produce food but some other commodities (crafters) or services (priests for religion, warriors for protection, etc.).

By producing surplus the farmer increases his standard of living above the 24 eus, which might equal for example the standard of living of a medieval serf. Depending on the interest there is for different kinds of services the standard of living of crafters and other servitors may be considerably higher than that. One cannot truly say that a servitor consumes e.g. four times as much food annually as the serf, but it is nonetheless true that such a servitor's standard of living is higher. In addition to eating more and finer food he gathers material wealth and/or has more free time. For example (from Pendragon), an ordinary knight requires 480 bu. to support himself and his squire, 480 bu. to support his mounts, and 480 bu. to maintain his family, or a total of 1440 bu. per year (= 60x24 eu). In a medieval setting the serfs must ultimately pay this (not counting special considerations like mines or fares on the knight's land) and in fact much more: men-at-arms, crafters and taxes to king and church. In return they get protection from wild beasts and robbers.

Crops: The three most important aspects of different crops are crop cycle, yield in bu. per land area (I'll be using acre, which is about 0.4 hectares or 0.004 sqkm or 0.01 sqmil) and yield per seed. The crop cycle tells the time from planting to harvest and together with the length of the growing season defines how many crops a farmer is able to grow per year. Other important figures are how much the land is consumed by the crop. These figures, especially yield per land area and yield per seed vary tremendously with agricultural tech level. For example European agricultural practices changed radically in the late 18th century so that erosion was carefully prevented and animal and plant wastes were used to refertilize the soils, which results in fertility increases of 1-2% yearly (or 10-22% in 10 years).
In medieval times the yield for wheat was about 3-4:1 for 8 bu. per acre (2 bu. of seeds). In common usage was the 3-field system, where 2/3 of the worked land was in use at a time and a third was resting or used as a pasture for animals. So a peasant holding consisting of 30 acres of cropland (quite large for English peasant holdings in the C11 - C14th) will actually have only 20 acres planted in any one growing season (the other 10 lying fallow/used as pasture) and requires 40 bushels of seedcorn and will produce 180 bushels in an average harvest. 

Basically only one crop per year was feasible, but on some areas also winter crops were planted. For other European crops yields were: 

barley, 4:1 yield
oats, 2+:1 yield
beans & peas, 4:1 yield

Rice is a very efficient, although labor intensive, crop. The yield may be as big as 50:1 (the seed rice is sprouted in nurseries and planted out, so there is very little wastage.) for 60-120 bu. per acre (1-2 bu. of seeds). In tropical areas with irrigation and a full-time growing season, the cropping cycle for rice is 100-105 days per crop. In such regions, it is usual for a farmer to have a number of fields with staggered cropping cycles, to keep the demand for water and labor constant. A crop of rice requires 400-800 person-hours of labor per acre.

Why are there so many Chinese? Abridged answer: western agriculture on 3 fields used to keep one fallow per year and grow two crops; in China, once they developed "wet rice agriculture" they could grow three crops a year every year because rice didn't "burn" the land; then they discovered they could plant and harvest twice a year -- result six crops a year -- of course it was labor-intensive, but then you could support the labor that way, so after a while, given the essentially Malthusian nature of the pre-industrial economy, there were three times as many Chinese per arable acre as there were western Europeans. Also corn is pretty efficient, although I don't have any numbers on it.

Crops and society: The irrigation requirements of rice require a very well-ordered society, with co-operation between farmers as to the timing offset of crops (so that one field is ready to be flooded when a field higher up the same slope is ready to be drained). For this reason 'water societies' are very important in the social and political lives of Javanese farmers, the basis of mediaeval Javanese government. (By the way, either the Javanese of the Balinese have a traditional calendar with 216 days per 'year'. There are no seasons, but the traditional length of a rice cropping cycle (108 days) is very important.) 

In Europe, the basic crop was wheat, which required draft animals to grow efficiently, and allowed the wide-spread use of horses as transportation. This, of course, led to cavalry, and feudalism in general. In China, rice allowed a high population, but was very labour intensive. It didn't encourage horses, but allowed farmers to produce surplus, allowing for a high percentage of non-workers. In the Americas, the Incas grew corn, a very efficient crop, which gave them loads of free time in which to develop an advanced civilization. It DIDN'T, however, allow for any kind of beasts of burden and coupled with their lack of the wheel (they knew about it, it just wasn't useful in their mountainous terrain), they were no match for invading Europeans.

The nature of crops also greatly influences the kind of society that evolves. This is true even, or especially, of non-food crops. The difference between cotton and coffee, for example, is extreme -- one breeds a chaotic and somewhat temporary society -- the other requires very centralized power and a very hierarchical society -- bad news for the attempt to build a cotton oligarchy in the American south! Greatly oversimplified: cotton grows fast and easily, but burns the land it grows on. Cotton-based societies have to keep moving, as the American South did as the land of Virginia, then Georgia, etc. got wasted. Keeping the same plantation in hand for generations didn't make economic sense, and in modern cotton growing countries it is not unusual for cotton to be grown on rented lands. Burning a cotton crop does not prevent growing cotton on the same land next year, so recovery from social violence or war is easy, although recovery from the damage the crop does is not.

Coffee, on the other hand, has to be grown for five to seven years before a single crop comes due. After that, you can get an annual crop forever, for coffee does not destroy the land it grows on. But if the bushes are destroyed by violence, then another 5/7 years must elapse. It requires very rich people indeed to wait that long for their first crop, and, in fact, the active support of a very strong government to enforce the social order such a crop requires. Thus, the oligarchical rule of Sao Paulo province in Brazil, or the coffee-growing areas of El Salvador (as contrasted to the cotton-growing areas of the same countries). Cotton economies and societies are chaotic, Coffee economies are well-ordered.

Animals: As the peasants were well aware you get a much higher yield from crops than cattle. The purpose of animals was to provide fertilizer, something special for feast days and something for the Lord's table when he had a bad day hunting, not to be a major or even a significant part of the diet. One pig at Yuletide, a cow for milk, a few chickens for eggs was about it for common people. The higher social classes were much bigger consumers of meat. Selling animal products to them might perhaps be an additional source of income for serfs? Scientifically speaking, when you eat something, you only retain 10% of the energy, the other 90% is lost. Example: if you have 100 tonnes of biomass at the first trophic level (grass, flowers etc), then you will have 10 tonnes of primary consumers (herbivores), 1 tonne of secondary consumers (carnivores), .1 tonne of tertiary consumers (humans, similar stuff).

A common approximation is that each acre of pasturage supports animals which yield 2 bu. of food annually. Another approximation: the pasture will produce 50 bu. of _animal_ fodder per acre. The requirements of different animals per year are 1000 bu. for horses, oxen and cattle, 200 bu. for pigs, 80 bu. for sheep and coats and 0.75 bu. for fowl. Chickens are not explicitly fed, they forage in the village. Goats will graze in the rougher areas cattle and sheep won't and can forage a much wider range of landscapes. They will also make the landscape more disposed to erosion. Pigs are fed partially from the garbage heap (although in bad times the edible value of the garbage decreases substantially). 

Land division: According to the Domesday figures (which relate to land use in England in 1086), the division of the land near villages was: arable 35%, pasture 25%, forest 15%. The rest was marshland, mountains etc. 'Forest' means land reserved for hunting as well as actual woods. This didn't change a lot until the 20th Century, apart from the 14th century population crisis when much more land was ploughed up. Another division (from C&S I think?) is: 30% forest, 20% waste, 10% cropland, and 40% pasturage (1/4th of which is fallow cropland). Forest is used for hunting and raising swine. Waste is unused forest, heath, or desert.

According to HarnWorld, "three men can reap and bind one acre per day." It also says it takes two to four weeks to harvest, and that all able-bodied villagers take part. This comes out to 5 to 9 acres per able body. If we assume 4 able-bodies per family, then we have 20 to 36 acres per family (which BTW fits nicely within the range of farm holdings given in _Fantasy Wargaming_ i.e., 15 to 40 acres).

Using the Domesday figures for a family of 4+4 (4 elderly/children) with 24 acres of arable farmland. Employing a 3-field system they have 16 acres under cultivation, which was as much as they could handle. The rest 8 acres may be used as pasture in addition to which there was the community pasture (21 acres per family). For a yield of 8 bu. per cultivated acre of which 2 bu. must be saved for seeds, the family gets 6*16+(21+8)*2 = 154 bu. of food per year, or full 24 bu. for each 'adult', 12 bu. for elderly and children and 10 bu. for taxes and such. For good seasons a little more, for bad seasons a little less. In bad seasons people die and the animal population is cut back and must be replenished. In good seasons only so much food can be stored, and it's not going to last much longer than that winter, so bad times take a few seasons to recover from.

Hmm... note that in the above paragraph I haven't taken into account winter crops and probably missed thousand other things. By just a little changes (like the yield ratio or the amount of land in cultivation) the amount of food varies pretty much. A lesson on what happens if you start simulating economics when you don't really know what you are doing. Anyway, according to the Gies' "Life in a Medieval Village" a farmer was estimated to be capable of supporting a family of 3, with enough left to pay church tithes, rent, and still have a bit of spending money.

Today the amount of woodland is: England 7.5%, Netherlands 10%, Wales 13%, Scotland 17%, Italy 23%, France 27%.

Taxes: With the rise of the centralized government common people started to pay taxes to support it. The question is, how much did they pay? The answer is: as much as they possibly could. Whatever the income of the people the government will always find uses for their money, and since the government is usually the greatest wielder of power (and the simple serf the smallest) the taxes will generally be as much as they can while keeping the farmers alive.

Sometimes the tax was taken as an actual proportion of production; but more often it was taken as a fixed amount based on an assessment of the holding's potential. The assessment would take into account the size of the holding; number of livestock; quality of equipment etc. For example, in a certain area, families with an iron plough had to pay 6 shillings; whereas families with a wooden scratch-plough had to pay only 3 shillings - presumably the iron plough was far more productive. The assessment was typically not conducted every year but more like once in ten or twenty years, or even less frequently in sparsely populated areas. Anyway, total taxes were likely in the 20-25% range (of total production), but occasionally upwards of 40%.

Taxes could, in addition to plain currency, be paid in various goods: grain, flour, animals, even beer. It was also usual that a farmer/serf would own a workday or two per week for his landlord.

The excuses for taxes vary ranging from understandable to ridiculous. Wars have always been times when the king establishes new temporary taxes to get money. After wars the taxes have had a tendency to become permanent. Plus, maybe there's a toll road on the way to market, and fees for attending the market.

On the other hand the farmers are also an active element in taxation, especially in terms of getting around it. For example a common way to collect taxes was to take a certain part (2%, 10%, 1 pint per acre, whatever) of the harvest. The farmers then hid some of their harvest and blamed on bad season when the tax collectors arrived. Those who got caught were of course severely punished, but that didn't stop farmers from trying, especially if the taxes really were unbearable. In desperate situations the farmers sometimes mounted a rebellion. These were usually quickly crushed, but they sometimes gathered the king's attention so that the worst points of the taxation system were corrected/removed.

If someone failed to pay his taxes his lands might be impounded and given to someone else who was able to pay the taxes instead. Especially the church could in hard times also forgive all or part of the tithes for that year.

When societies expand to previously uninhabited areas the problem typically is to get enough commoners to live there and work the land. Many strategies were adopted to encourage colonization. For example Lords might offer to waive military service and/or charge zero rent for the first 7 years. Also landholdings were typically larger in newly colonized areas.

A concrete example from Bartlett's "The Making of Europe": Brandenburg around 1300 was an area of new colonization where the tax/rent burden was relatively low to encourage settlement. The standard peasant holding was a "mansus" of 40 acres. It was not uncommon for peasants to hold more than one mansus. A mansus could easily produce 120 bushels per annum. (Two-thirds of the mansus would be sown at 1.5 bushels per acre with a yield of 1:3). The total burden of tax/rent/tithes was 26 bushels per annum. This works out at about 20% of production. Note that this is an example of a low-tax area. It is contrasted with England where the dues were supposedly 50%+.

built by unclefester | sternzwischen | updated 14-05-29 23:15:25