Demographics are a popular issue to talk about, within political, geopolitical, and economic groups, pretty much all have a concern of some sort. I would like to add history to that list to demonstrate how all of these come together, and what that might mean for the future.
Populations are not generic of course, and the self-identified differentiation between them is usually enough of a shorthand to see where practical considerations will lie, but there are also harder factors that will dictate the boundaries. These groups often have their own cultural spheres, their own hierarchies and leadership networks, and will find themselves on their own path in relation to others – even if they sometimes reside near one another geographically. There is often a geographical consideration, but it does not seem to be definitive compared to other circumstances; both material and spiritual.
As an example of these factors coming together – Phoenician colonisation appears to have been fairly regular during its golden age, as a method of maintaining safe and reliable trading routes. Their colonies sprouted up at roughly 30-50km intervals along profitable trade routes. Some remained as small outposts, while some – such as Carthage in modern-day Tunisia – grew to be much larger, rivalling Rome in its time, and growing to set up its own colonies. The famous fertility of the region could explain its growth, or prime position for a maritime empire at the centre of a great trade network and possessing an excellent harbour. However, there is another compelling theory that Carthage’s growth is thanks to a large population of religious fanatics who were cast out from their home of Tyre. Part of the reason this explanation is so compelling is because it is highly evocative of the nearby Greek method – wherein as a matter of fairly standard practice, once a city became too overpopulated, or a number of families too overburdened with excess adolescent children whom they could not provide for on their meagre ancestral land – they would be sent to form a new city along the same parameters as their home. Often they worshipped many of the same gods and heroes as their home until the two gradually drifted apart once their interpretation of the will of the gods drew them to take on different customs. Still, however, this bond would remain, and through it – they could confidently recount their lineage leading back to the gods themselves. In both of these cases, what is fundamentally required – is an excess population which can be cast out either as a necessity, or convenience. So too, millennia later did Britain face the same problem, exporting its discontents, radicals, and utopians to the Americas – rather than letting them agitate and tamper with the status quo at home. Each in turn eventually came to settle on a more stable, normalised status quo, albeit with much of the same radicalism built-in, and the fervour which carried them to launch their own colonies westwards.
More recently, during the Ostsiedlung; the eastward expansion of the Germans into formerly slavic and baltic lands, and the intensification of existing land use – was dominated by the simple fact that the Kingdom of Germany’s population expanded from 4 million to 12 million from the 11th to the 13th centuries. This coincided with the Medieval Warm Period, which saw usually temperate climate conditions raise the productivity of much of Europe. Many of these people flooded into the borderlands and marches – less closely scrutinised areas of the Holy Roman Imperial sphere which developed into many of the larger landholdings and more nimble polities which dominated the empire later. Beyond this – they spilt out further east – settling all along the Baltic coast (notably in Prussia), making inroads into what is now more commonly known as the Sudetenland of Czechia, and Silesia. This is only half the story, however.
The expansion of the Germans was only possible thanks to the low population density of the Slavs whom they overtook. This is a very familiar story, however, and the same basic outline applies to the Slavs themselves during their earlier initial expansion westwards, particularly into the Balkans. In many places, the land was so under-cultivated that there was no particular conflict, with existing settlements untroubled by the new arrivals who – if anything – brought a material boon to the area by providing new goods and markets for the existing inhabitants. If the settlement was conducted with the approval of the local lord – they would likely also bring additional taxes in either coin, labour, or goods. Over time, depending on the particulars of the scenario, and the levels of population displacements/migration/fertility, one group would tend to assimilate the other over time, leaving a single dominant culture, with perhaps some enclaves clinging to their old identity. All of this was only made possible in the first place; by insufficient fertility, and thus population to maintain the extent of their lands that they inhabited. And conversely, nearby people find themselves with insufficient land compared to their number.
One might raise the reply that only means are required – and prior to the modern age, these means were supplied largely by sheer numbers of people alone. In the modern-day, sufficient technology will suffice, it might be said. Closing on the present, however, this often seems to be the opposite of the case. China, South Korea, and Japan all channelled their population explosions towards economic ends particularly, and burned the bridges behind them – giving them each a meteoric rise, followed by slowing, and in the latter two cases – stagnation. It remains to be seen what the full consequences of the fertility slump will be. In Germany and Russia meanwhile, the population explosions were channelled towards a mix of war and industry – at first scaring their rivals, but eventually slowing and faltering. With one generation of lag, these fertility spikes (relative to child mortality), do a fairly good job of predicting future prominence – historically militarily, but more recently, economically. Further back it was still possible to bypass the imperative of sheer quantity through a baby boom among a population capable of punching above its weight – usually due to circumstance, such as when the Arabs and Turks enjoyed the patronage of wealthy empires – allowing them to both drain the native martial strength in the long term through lack of investment, and grow their own numbers through prosperity, until they are capable of displacing their former patrons, and setting themselves up as rulers in the 7th and 11th centuries respectively. In fact, once against the lack of population issue rears its head in 11th century Byzantium when the Byzantines hired Turks to garrison many of their fortresses due to a lack of Greeks for the purpose (though I’m sure political considerations also played a part), such that a setback in warfare against the Turks gave the garrisons the opportunity and impetus to defect, and take vital towns and forts with them.
Rome staved off the decline for far longer than most others by exporting its people in colonies which either went semi-native and adopted some of the ways of the populations around them or maintained the old Roman virtues for longer, and their fertility along with them – while the mother country degenerated; first ceasing to provide legionaries, then emperors, until it was largely left to Hispania, Africa, and Illyria in turn to provide.
It may be that this is simply reducible to manpower, firepower, and computing power, and that for the first time in history – we have transcended the need for additional people through robotics, ordinance, and computers, but I would suggest that more may be at play. Either decline in fertility and general decline have the same psycho-spiritual source, or there are severe psycho-spiritual consequences of low fertility. The toll that it takes on a family to be meeting more often for funerals than for weddings and baptisms would not be so easily remedied by drones and supercomputers. Or perhaps, a people which cannot be roused to perpetuate itself – will make no other sacrifices for the sake of something greater than themselves – like progress or empire. Indeed it seems many mothers through time would not allow their only sons to be sent off to war, and aged cultures are – it stands to reason – generally more risk-averse. A culture that is predominantly populated by older people will tend towards caution and maintenance, rather than adventure and imperium, for biological reasons if nothing else. A people which in totality – voluntarily and enthusiastically embraces the abyss is even less likely to achieve imperium, albeit they may still leave great triumphs of will in their wake, a much better fate than death by apathy, but still not ideal. For these reasons, a fresh will to proliferate and grow as a people is perhaps more important than ever, because our means are so greatly increased that we magnify every whim. If we wish to die, we can do so in the historic blink of an eye, but if we will ourselves to grow and conquer, the stars are within reach.