What kind of demographics are we talking about?

[Kevlar]

As I was about to start fleshing out the map, factions and history of the Harronyne I reaized something: there's no information about the archipelago's demographic. Sure, West Emperor Island is highly populated, but what does that mean to the archielago-eans? 100,000? 500,000? 1,000,000? 25,000,000? What figures are we looking at? And what's the population growth? Has there been a boom after the Cataclysm along the lines of 1% growth a year? More moderate at 0.1%? Or has it been slow, like 0.05%?

Sure, each area is sure to have its specific numbers, but it would probably be best to have some sort of baseline.

 

[Ravana]

Well, it's fantasy, so at least some of that's flexible. As a baseline, though: in Medieval and Renaissance Europe, 30,000 inhabitants was a big city; even 5,000 was considered substantial. Not that larger is impossible: conservative estimates of Rome during the Empire period start at around half a million; some Iberian cities during the Muslim period were over 100k; some Asian cities were of similar size… for whatever reason, Europe didn't support large cities well, until shortly before the Industrial Age. (I'd guess that at least part of that was because of Feudalism, which encouraged widely distributed populations rather than concentrations thereof—especially where mobility was illegal.) Kilvikasa, the trade city we've put on the central northern coast of Emperor Island, is loosely based on Constantinople, which, throughout much of the above period, had a population hovering around half a million; I'm thinking our city will be a bit smaller than that, but probably not much (physically, at least, it's roughly the same size, though it lacks some of Constantinople's advantages).

And the overwhelming majority of the population didn't live in cities. Up to the 18th century, the most urbanized region in Europe only had 30% of its population living in cities and towns; 10% was considerably closer to the norm. Population estimates vary widely, but a reasonably good estimate was that during the time of Charlemagne, the overall population of his realm had a density of 15 or so persons per square mile. This is an average, of course: mountainous, forested and swampy areas would have had less, fertile plains considerably more. But that might provide at least a baseline to work with.

As for growth: I'm assuming that the first generation after the cataclysm was pretty much too busy surviving to do much more than replace its losses… if that. Starting with the second generation, populations would start to rise again; by the time the third started having children—certainly by the fourth—they would probably be nearing pre-cataclysm levels. In any event, three centuries is more than enough to see it reach its previous equilibrium, and possibly surpass it, until natural forces (available food being the biggest one) caused growth to level off, so I wouldn't worry too much about growth rates: they'll have caught up by now. (Pre-industrially, populations tended to remain fairly constant, barring events such as the Plague or the Thirty Years' War, and recovery therefrom.)

"My" areas—the Plain and the Savage Coast—aren't necessarily representative, especially the Plain, which is inhabited by subsistence-level nomads. I'd guess their total population is less than 100,000—in a 400k-square-mile semi-desert. The Coast has a number of small towns (none larger than 5k), with a scattered agricultural populace; roughly 1,000 miles of coast, with "usable" (loosely speaking) land varying from 50 to 100 miles inland… call it 100k square miles, with a lower than average density, especially the farther inward one goes: probably between half and three quarters of a million people. Maybe a million; certainly no more than that.

That having been said: if your culture is different, if your resources are different, etc., you could have considerably less or more than that. If you have a grain crop that produces three yields a year, you can support a vastly larger population; if most of your land is wilderness, it will be that much less. I don't think we've actually discussed whether or not (or to what extent) there are intelligent non-human races, but a small change in terms of dietary requirements could significantly alter these numbers. If your society more closely resembles Muslim Europe and the Middle East—that is, centralized rather than Feudal—it might go in for larger cities. Much of the coastal area would have been devastated… and cities are commonly located on coasts: some parts may never have recovered, and coastal cities might have fallen out of favor in preference for smaller settlements located on higher ground. Conversely, if the coasts were highly populated, and much of the population survived but the lands were largely destroyed by inundation of salt water and erosion of topsoil, a flight to the cities may have occurred… as long as the inland areas were still resilient enough to provide the necessary food. And so on. So it's pretty much up to you. If you do anything that seems to defy ecological logic, I'll let you know.