[Mod] Settlement Populations

[BlackEagle78]

@NakedBeast

For consistency's sake I used McEvedy and Jones' Atlas of World Population History for every population figure. You can download a full PDF of it here https://www.fichier-pdf.fr/2014/12/21/pour-happliquer/ (the website is French but the PDF is entirely English).

My population figures are based on 867, though that applies almost perfectly to 769 for most areas, and in the worst areas is only off by ~20%. When I have the time I will update the map for exact 769 figures. I got those figures by taking the nearest dated population estimates in the Atlas, and extrapolating from there. Usually there are figures for 700, 800, and 900 CE, so it isn't that hard to do.

I can guarantee that the figures you see in game are accurate for the Atlas' estimates, with minor exceptions in some areas that fall well within the margin of error on historical estimates like this. The only areas that are not properly represented are Egypt, Yemen, and India, where some provinces need to have more than 300k rural pops to reach historical figures. Ideally, the Nile Delta, one or two Yemeni highland provinces, and the entire Indo-Gangetic plain would have 100k population per holding.

The figures only become significantly divorced from the Atlas when it comes to carrying capacity. With the current number of provinces, virtually all of France and Germany and a few other European regions would have full holding slots, making it impossible to represent subregional differences. For that reason, holding slots were reduced in some areas to make the holding slot distribution line up more with a map of early modern population density. I'd estimate that the carrying cap is reduced in some areas by up to 20% of what it should be, but I felt it was acceptable given that we're dealing with generally rough estimates, and that it isn't an exact science to translate historical population figures into carrying capacity.

India is the only place where there are huge problems. I based carrying capacity on max population achieved before 1700 (or in some cases 1650), reasoning that agricultural technology and crop usage didn't change dramatically in Europe until after that point. Presumably, in an ideal situation (e.g. a major centralized pan-European empire with no frequent wars, and with no Black Death), these figures should be reachable even by 1453. But in India, the population in 1500 (my old carrying cap cutoff date) was ~100 million. In 1700, it was ~160 million. That's an average of 8.7 versus 14 holdings per province. Even in the former case, and with the Indo-Gangetic plain provinces buffed immensely, India is still mostly a blob of provinces with 7 holding slots. In the latter case, it would be much worse.

India can look somewhat sane with 100 million max pop, so I went with that. I think a detailed, realistic map of India can be made with TwiddleFactor's variable carrying capacity, but to work with variable carrying cap per holding, the holding slot map will have to be redone for the entire world.

That source was published in 1978; as of now, it is 39 years old (!). In that time, there have been many archaeological discoveries and demographic studies which have increased our knowledge on historical demography. One blatant mistake I found was the map of populations in 200 AD, where it was claimed that Germania and Asia Minor both had about six million inhabitants; not only was Asia Minor quite urbanized whereas Germania was not, Asia Minor could rely on grain imports (from Egypt), heightening the carrying capacity, whereas Germania was autarkic and had to rely on what they could grow themselves, severely lowering the carrying capacity.

Also, for the maximum carrying capacities in general, don't forget that in most parts of Europe, the population only got back to pre-black death levels around 1700. Seeing how the plague itself followed after a dip in population levels, I suggest you don't use 1700 as a reference to determine the maximum carrying capacity of the provinces in this otherwise quite interesting and promising mod.

 

[Eternal Phobia]

I thought it was a bit low too, but I assume the authors were aware of the devastation caused by the Mongols, and yet still didn't give Iran a bigger early medieval population.

I am generally skeptical of their figures outside of Europe, but I won't make changes in the absence of other sources of similar quality. I've seen estimates of Iran having up to 10 million before the Mongols, and of Iraq having up to 5 million, but not as part of systematic studies.

No, no, no, what I mean is that the Iranian and Iraqi populations might have been at 5 or 2 million at their highest prior to the sacking of the areas by the Mongols, and this might even be fairly accurate, but it's probably not a historically accurate maximum carrying capacity. The Mongolian sack of Baghdad destroyed not just the city of Baghdad, and killed hundreds of thousands of people, but it also destroyed the infrastructure that supported agriculture in the area. Some historians have said that the damage from the Mongol invasion was never healed and is a major cause for why the Iraqi population is so small compared to what you would assume historically. Consider that Iraq was the bread basket of the Sassanid Empire; that doesn't exactly match up with what you would determine from your sources. Consider also that the Mongolian invasion of Iran was as disastrous for Iran as their sack of Baghdad was for Iraq; perhaps even worse. Prior to the Mongolian invasion, Iran was actually continuously populated. As you might expect based on what happened to Iraq, the Mongols destroyed the canals that ran through Iran and enabled an agricultural society. Some estimates have said that 90% of the Iranian population was killed by the Mongols; at the very least, one in four was. This then happened again when Timur conquered the region. All of this destruction makes it very hard to use historical numbers in order to calculate the carrying capacity in the Middle East. The Mongol conquest didn't just kill millions of people, it also salted the ground that those people had farmed for centuries.

EDIT: I suppose an interesting feature this mod could have would be the ability to construct canals in provinces in order to raise their carrying capacities, and then these canals could then be destroyed by invading armies in order to model how dependent areas like Iraq and Iran were on canals in order to support their populations.

 

[TwiddleFactor]

Right now Canals are just part of an "irrigation" building chain in all of the settlements, but I suppose making them a province modifier might make more sense.

I could add an event chain similar to the tower architect chain for building irrigation works in provinces.

 

[mudcrabmerchant]

That source was published in 1978; as of now, it is 39 years old (!). In that time, there have been many archaeological discoveries and demographic studies which have increased our knowledge on historical demography.

Unfortunately I'm not aware of specific sources available free online. I'd appreciate sources and/or sourced figures for specific regions if you have any.

One blatant mistake I found was the map of populations in 200 AD, where it was claimed that Germania and Asia Minor both had about six million inhabitants; not only was Asia Minor quite urbanized whereas Germania was not, Asia Minor could rely on grain imports (from Egypt), heightening the carrying capacity, whereas Germania was autarkic and had to rely on what they could grow themselves, severely lowering the carrying capacity.

I think you're misreading the Atlas if you're seeing 6 million for Germany in 200AD. The figure I see is 2.5 million, which is perfectly reasonable. Germany has a lot of arable land.

Urbanization does not on its own increase carrying capacity, it's more a product of an existing high carrying capacity. Food imports can transfer carrying capacity from one region to another, by allowing the importer to support larger cities than they would otherwise be able to, but long-distance food imports were completely reliant on water for transportation, and Anatolia doesn't have a lot of long navigable rivers. And even Anatolia's coastal cities (which would be the only ones that could use Egyptian food imports) were not exceptionally large, unless you count Antioch, and even then it's at best a few percent of the total population of Anatolia.

I'm pretty sure that the only places in the ancient world where long-distance food imports had a huge effect on total population were Italy and the southern Balkans, where Rome and Constantinople at their heights would have made up a significant percentage of the population.

Also, for the maximum carrying capacities in general, don't forget that in most parts of Europe, the population only got back to pre-black death levels around 1700. Seeing how the plague itself followed after a dip in population levels, I suggest you don't use 1700 as a reference to determine the maximum carrying capacity of the provinces in this otherwise quite interesting and promising mod.

So do you suggest raising the cap for Europe? It's already very high, and the sources I've read seem to indicate that Europe was already reaching it's carrying capacity just before the Black Death. That's not completely the case, as a lot of Europe increased in population significantly over the pre-plague high by 1700, but the actual carrying capacity probably shouldn't be much higher than the pre-plague levels.

Personally, I find Robert Brenner's theory convincing. The gist of it is that before the Black Death, European population growth stagnated because all the land had been taken, and the existing social structures disincentivized efforts to improve the productivity of the land - which explains why parts of Europe were able to increase in population past the pre-plague high, even before the Agricultural Revolution or the introduction of the potato. However, I'm no expert on medieval and early modern demography, and I don't know what the modern academic consensus is.

 

[mudcrabmerchant]

No, no, no, what I mean is that the Iranian and Iraqi populations might have been at 5 or 2 million at their highest prior to the sacking of the areas by the Mongols, and this might even be fairly accurate, but it's probably not a historically accurate maximum carrying capacity. The Mongolian sack of Baghdad destroyed not just the city of Baghdad, and killed hundreds of thousands of people, but it also destroyed the infrastructure that supported agriculture in the area. Some historians have said that the damage from the Mongol invasion was never healed and is a major cause for why the Iraqi population is so small compared to what you would assume historically. Consider that Iraq was the bread basket of the Sassanid Empire; that doesn't exactly match up with what you would determine from your sources. Consider also that the Mongolian invasion of Iran was as disastrous for Iran as their sack of Baghdad was for Iraq; perhaps even worse. Prior to the Mongolian invasion, Iran was actually continuously populated. As you might expect based on what happened to Iraq, the Mongols destroyed the canals that ran through Iran and enabled an agricultural society. Some estimates have said that 90% of the Iranian population was killed by the Mongols; at the very least, one in four was. This then happened again when Timur conquered the region. All of this destruction makes it very hard to use historical numbers in order to calculate the carrying capacity in the Middle East. The Mongol conquest didn't just kill millions of people, it also salted the ground that those people had farmed for centuries.

I'm fairly well convinced that McEvedy and Jones are underestimating the historical populations of Iraq and Iran.

If Iraq at its height had only 2.5 million people, and Baghdad at its height had 1 million, just Baghdad alone would give Iraq a ridiculously high urbanization rate of 40%. That might be possible in an area with really efficient agriculture, but Baghdad was not the only city in Iraq. For comparison, the Netherlands during the Dutch Golden Age had 55% urbanization, but it had to import a lot of grain from the Baltic, and Abbasid Iraq didn't have anywhere to import large amounts of grain from.

Unfortunately, lacking alternate sources, I don't have other figures to go off of.

 

[Mitusonator]

I'm fairly well convinced that McEvedy and Jones are underestimating the historical populations of Iraq and Iran.

If Iraq at its height had only 2.5 million people, and Baghdad at its height had 1 million, just Baghdad alone would give Iraq a ridiculously high urbanization rate of 40%. That might be possible in an area with really efficient agriculture, but Baghdad was not the only city in Iraq. For comparison, the Netherlands during the Dutch Golden Age had 55% urbanization, but it had to import a lot of grain from the Baltic, and Abbasid Iraq didn't have anywhere to import large amounts of grain from.

Unfortunately, lacking alternate sources, I don't have other figures to go off of.

What if majority of Baghdad population actually worked on agriculture but lived within the city boundaries ?

 

[Zenneh]

I have a small suggestion as silly as it sounds:- Would it be possible to provide tax cuts/Provide cheaper health care decisions as modifiers to holdings to improve their pop growth? Any new holdings that are created take a long time before they even get rid of their negative modifiers.
I feel I made a huge mistake giving the new holding 500 pop as it will take about 200 years to get to about 10k pop at about 2% growth rate.

On another note does migration actually happen between holdings? Or does migration just lead to disappearing pop? I was thinking of raiding a huge population stuffing it into my capital and hope that they all migrate into my other holdings.

 

[NakedBeast]

I feel I made a huge mistake giving the new holding 500 pop as it will take about 200 years to get to about 10k pop at about 2% growth rate..

Thats a crazy fast growth as it is

 

[Capinacci]

This mod looks amazing! Good job!

 

[Klein001]

Hey there. Love the mod.

That being said, forgive me if this is a poor place to put this, but after a fairly methodical testing I have found that the mod will reliably crash the game if I build a settlement in any province that isn't my capital province. Checking the logs reveals an ACCESS_VIOLATION error.

After trying to track down the source, my current best guess is that the access violation comes from the current_capital event target not being set to anything whatsoever.

For this, I can suggest fixing the scope in one of two ways:

1) scope to the nearest capital

for this, I assume that the event target newly_built_settlement is a title scope, but if you're trying to draw from the capital holding of the province then I would suggest the following scope scheme:

vent_target:newly_built_settlement = {
location = {
capital_holding = { save_event_target_as = current_capital }
}
}

Based on the wiki, this should reliably scope to the capital holding of the most relevant province (e.g. hedesunda in Gastrikland, or Kastelholm in Aland)

2) Scope to the capital holding of the capital province

if you instead intended to draw from the capital holding of the capital province without fail, then I would suggest the following scope scheme:

capital_scope = {
capital_holding = { save_event_target_as = current_capital }
}

Whatever you do, I can personally say that method 2 works perfectly. I just tested it.

Edit: As an addendum, I just discovered that the mod also does not like it when a tribal holding completes construction. This also causes crashing in spite of the fixes I suggested above.

Edit2: Through further testing I found that the above behavior was not actually specific to tribal holdings and was intermittent. I will continue to monitor it, but the fix appears to be holding.

 

[TwiddleFactor]

Been away for a while, but I'm hoping to put out a small update soon. I thought I had fixed the crash on settlement build, but I'll have to look at it again.

My original goal was to have it take from the character's capital settlement, rather than the province capital.

 

[TwiddleFactor]

I just uploaded a new version of the mod. Originally I had only planned to make small bug fixes, but I realised there were a lot of half finished features in my most recent version, so I finished those. The ai decision making still needs some work, and the balance isn't great at the moment, but all of the new features should be working as intended.

One of the largest changes is the addition of a population dependent revolt risk. Basically the higher the population in a settlement, the larger the risk of revolt in the settlement's province. Cities, especially ones held by republics and temples have lower revolt risks, and castles have the highest revolt risk. The peasant revolt cb, which will usually be the one that fires as a result of the population induced revolt risk, now also creates a republic instead of a feudal realm.

Another big addition is the addition of demesne taxation control and buildings that track the level of personal control a holder has over a settlement. In my mind, castles and temples represent land that is fully owned by a feudal lord, and a theocracy respectively. Based on this, in addition to the taxation income that the holder of a temple or castle receives, they will also gain a yearly flat income that represents their personal income from the land. In the case of cities, they will originally only give tax income, but buildings that represent the ruler's personal land in the holding can be purchased. Once you reach the third level of the ruler control building, it is possible to convert the settlement to either a castle or a temple. In addition to this, there is now an obligation law for the tax level in your personal demesne. Higher tax rates will increase income, but will also increase the chances of revolt in a province.

The main reason for the taxation changes was that I felt it was somewhat strange that mayors held so much wealth. Cities themselves should be rich, represented by their base tax value (which contributes to the province wealth), but the actual personal income of a mayor should be less than a feudal lord. In addition this change makes it possible to represent tax farming, where a noble (feudal lord) is given the tax rights to a settlement without being given actual land ownership in the province. To properly represent cities though, I intend in the future to find some way of representing the minor landholder/bourgeoisie's wealth in a settlement and allow buildings to be built automatically in cities when this wealth passes a certain level.

I hope everyone enjoys the new changes. I need to do some play testing in order to improve the balance, but if anyone is brave enough to give this a shot, let me know what you think.

 

[Figus]

Is there any word on compatibility with HIP. I understand the mod is still being developed, but as it stands the only problem with it being used with HIP right now appears to be the fact that the Byzantine Empire is a merchant republic due to none of Constantinople's holdings being castles.

 

[TwiddleFactor]

The main incompatibility is the history files, but there are a few other incompatibilities as well.

I was originally planning to revamp buildings as well as add the population system, but in order to preserve compatibility, I think I will refrain from this. I was finding that I was having to change more and more just to model realistic income and buildings.

I will be tidying up the mod files a bit over the next few weeks, and will soon release a version that doesn't cover such a large scope.

The main components in this version will be,

Population that increases levy, garrison and tax income
Revolt risk based on population
Population growth mechanics (migration, growth and import of food)
Demesne tax levels that affect revolt risk
Family palace bonusses based on merchant republic capital size

Most of these features are done, I just have to clean up the mod and remove the overall building revamp that I was working on.

With the upcoming version, compatibility should be much easier to obtain. There are some events in HIP that could cause problems though. For example, in Ck2+ there is an event for a courtier to build a temple. Currently my mod wouldn't give such a temple an initial population, and so the temple would be deleted when my mod's yearly population check is run. If HIP has similar events, the same problem would exist.

If there aren't any events like the one I describe in HIP, you can just delete the history folder in the current version of my mod and I believe it should work resonably well. I can't give any guarantees though.

 

[Figus]

Alright, in that situation I'd like to say that, having played a recent tribal game in ireland, there are in fact events for characters to build both bishoprics and cities. Thank you for the answer though, and I don't think that it'll be too hard for me to make this a non-issue, and if it is I'm fine with spending some time to do so. Thank you for the information by the way. My primary interest in this mod is just because it'll really help me with megacampaigns between HIP and M&T because in the past I've been doing weird, awkward, and likely wrong calculations to determine pops.


EDIT: Looking at it, the easiest fixes would be to just delete your mod's history files and EMF's emf_builder_events file.

 

[TwiddleFactor]

Ya, it would probably be a good idea to remove all the references to specific cities from the first event in my event file as well. If you don't do this, those settlements will have massive negative growth at the beginning because they won't have anybof the necessary buildings to sustain their high populations.

If you can wait a few days, I would suggest waiting till I upload the next version before starting a new game though, there are few save incompatible changes that I will be making.

 

[Figus]

I'm not trying to rush you or anything, and I really appreciate the fact that you've even made the mod, but it's been a bit more than a few days.

 

[TwiddleFactor]

Ya, sorry about that. I made all the changes a while back, and was planning on uploading it. I just got a little busy and never had the chance to do bug testing.

Hopefully I can find some time this weekend.

 

[TwiddleFactor]

Just finished checking my code, and I think the new version should work without any bugs or oversights.

The new version adds several new features, such as a supply system based on the population in provinces. Still working through things though, so balance might not be great at the moment. I have also made several updates to the carry cap bonuses and growth calculations. Unfortunately, the large changes I have made to the buildings makes the new version incompatible with the old one, but I personally feel it should play much better now.

In addition to this, I have recently been trying out CK2Plus and have made a CK2Plus version. The many events they have to create holdings required me to mod quite a bit, but I think I caught them all. If anyone has the chance to try it out, let me know how it works. As far as I know, HIP shares a lot of these events with CK2Plus, so when I have the time I might try to make an HIP compatible version as well.

I'll be updating the opening post over the next few minutes. Let me know you feel about the updates.

 

[Maximius]

Can't wait HIP version to try out this mod, looks very interesting and promising.
Keep up the good work!