The aggregate of the 31 citadels is most often attributed to the decline in population. In ancient times as the population of the planet swelled unnaturally, people moved into cities that swelled into monstrous megaplexes of sprawling humanity.

However when population began to decline it struck hardest at the countryside. Suddenly cities became livable because they were not overcrowded. The majority of the population was urban and stayed urban. Hints at this effect had been seen in the many economic downturns experienced during the times of rising population. While jobs may have been lost for some, most found that housing became more affordable, services became kinder and crowds became less as people spent less.

The population decline meant that growth was no longer the driving economic force. A cheap labour force was no longer available to fuel that growth. Instead sustainability moved from being a laudable goal and the essential means for business to survive.

Cities provided the infrastructure and economies of scale necessary to support sustainable business, and so as the high tide of humanity receded, the remaining population washed up into the large cities. Eventually 31 of them shook out as the most successful.

Raising of the citadels
The citadel movement recognized the importance of these cities as part of the agglomeration of cities that began to supersede nations as the dominant powers. Nations still exist of course, but more as clubs and representative agencies for special interests than the governing powers they once were long ago. To separate the old subservient model of city government from this new more effective power, the citadel movement began.

It grew out of a separation of responsibility. In most of the 31 cities an older form of executive, usually the mayor, still subservient to national power began to transition into a ceremonial post. They’re seat remained in city halls and courthouses. The new executives rose out of regional bodies that ruled the real metropolis not the old imaginary borders set down by ancient towns long ago merged. These city managers distinguished their offices by calling them citadels. The name was meant to indicate this was the government of the entire population in the entire urban area not just for one city.

For instance in New York, the Mayor continued to reign over the five boroughs of New York City from city hall in Manhattan. But the Tri-State Ombudsman rose to prominence in his offices in the Empire State Building which eventually became the citadel of New York, covering New Jersey, Connecticut, Long Island as well as the five boroughs.

The first citadel is attributed Shenzhen, and was a brand new building created by the People’s Party there for the regional commander. More cities took New York’s tactic of naming an existing building as the citadel. A few because of quirks in geography have adopted a rotating citadel that moves every few years into a new building. The Los Angeles citadel operates under this model. But in all cases citizens speak of what citadel they are from. The few left in smaller towns like Chicago or Madrid for instance either identify with the nearest citadel, which their villages are dependent on, or call themselves farmers, a term once used to mean agriculturalists but now used to mean anyone living outside of the direct governance often of the 31.

Honorary Citadels
When speaking of the rise of the 31 citadels, it is worth noting that two cities are commonly referred to as citadels though they are not part of the 31. One is the Antarctic Citadel, built in celebration of the 100th founding of the 31. It is the tallest structure in Antarctica and houses the chief research scientist of the International Academy of Scientists mission to the continent. It also provides excellent labs and resources for research done there. However there is no real permanent population on Antarctica, and as such it has not requested nor required representation in the 31.

The other is the Lunar Citadel, built by the Space Agency in the early days after the founding of the 31. In fact some older texts will even refer to ‘the 32’ as hopes ran high that the Moon would become a full fledged citadel.

Sadly the dream was never realized and references to the 32 serve merely to date the text in question. The citadel exists and even houses a local government for both lunar and Martian activities. However much like Antarctica, the population cannot be considered permanent and consist mostly of international science and commercial efforts.

Both the lunar and Antarctic citadels have honorary, but non-voting, seats in the meetings of the 31. The Lunar representative rarely attends. The Antarctic mission usually sends a scientist from their citadel as recognition for some achievement. In other words, it’s a vacation.