Jerusalem
Jerusalem! City of God! Located at the exact center of the flat disk of Earth, at noon the towers of Jerusalem cast no shadow. The largest, most continually inhabited city on Earth, Jerusalem is also the most diverse. Aside from Christians, Jews, and Muslims, there are priests, prophets, wise men, and mad men of every imaginable sect and heresy. It is said that every race and creed is represented here. At any given time one can find the streets crowded with immigrants, emigrants, pilgrims, refugees, musicians, magicians, merchants, saints, princes, beggars, thieves, and whores. Humans are not alone in Jerusalem, for succubi, cambions, djinn, ghouls, Nephilim, and even the strange and fantastic races of far Indica rub elbows with each other as they go about their lives.
The Succubus Quarter is a crime-ridden slum, but the food, music, and art are like nowhere else in the city...and, unsurprisingly, it's a good place to go if you want to have a good time. In Little Indica one can find the spices of the far east, and the strange races that bring them along the trade routes from the Kingdom of Prester John (the neighborhood is also deeply in the pocket of the organized crime community). There are crowded neighborhoods home to the Marids, descendants of Solomon's slaves, and here and there are the massive houses of Nephilim who came in the retinue of one warlord or another.
The sheer volume of trade and pilgrimages ensure the city's gates are busy at all hours of the day, and the synagogues, mosques, and cathedrals of dozens of denominations rear their towers from Jerusalem's seven hills. The palaces of nobles and merchant princes crowd up against slums, market squares, and monuments, with holy shrines around seemingly every corner.
Dozens of peoples have entered Jerusalem as conquerors, and far more have entered as peaceful immigrants. Some assimilated over time and others persist to this day, but all of them add their own music, food, and art to the cultural melange. It has been said that Jerusalem's culture is like nowhere else on Earth, for it incorporates elements from every other one. Its architecture too is stunningly diverse, with a keen eye able to see the layers that have been laid down over time, buildings expanded and built on top of each other with newer styles, the bones of the oldest structures still poking out in unexpected ways. Some buildings have been in use continually for thousands of years, and always there is new construction going on.
Beneath Jerusalem lies the undercity, where a vast network of tunnels, tombs, and catacombs are home to a community of ghouls that rivals any in the world save the Valley of the Kings in Egypt. The ghouls have been living here as long as there have been humans on the hills above. They have been feeding so long that the leftovers of their meals have long since made their way into the very architecture of the place, pillars of bones holding up ceilings or shoring up the sides of tunnels, often with macabre and grotesque flair. While some consider this to be no place for surface dwellers, a substantial community of outsiders live here as guests, adopted family members, traders, and in numerous other roles. While outsiders make up no more than perhaps one in twenty inhabitants, it is said that in the torchlit markets one can find anything or anyone in a pinch. The ghouls are ruled by a council of family elders, and every so often a civil war breaks out in the dark and crowded tunnels as an extended family grows too large to be managed and splits, both branches making power grabs in the constantly shifting political scene.
There have been multiple attempts to invade the undercity and root out the ghouls, but the claustrophobic tunnel fighting combined with the fact that ghouls will feed on their own dead as well as human dead means that they rarely accomplish much besides feeding the ghouls for another time. As it is, the humans and ghouls live in a tense truce, with some humans even appreciating the service the ghouls do of cleaning up the city's bodies.
Jerusalem's government is as cosmopolitan as its people, with religious courts, councils of tribal elders, the scions of nobility, and neighborhood power brokers constantly jockeying for control of overlapping spheres of influence. There are meeting halls for the common folk and guild halls for the merchants, and the religious leaders even have a public debate hall where they constantly argue over points of doctrine. There is a city-wide police force and the bits and pieces of various bureaucracies that have been established by kings past, working together in a byzantine and inefficient conglomeration. Charitable religious orders, some publicly funded and some not, tend to roadside shrines and feed and clothe the poor. The tax collectors and the banks of Jerusalem are fabulously corrupt, but enough money collected on imports and exports through Jerusalem's gates makes it to the coffers of those departments that maintain the city's sprawling and haphazard infrastructure that it always seems the city will totter on for another decade.
(There are strict fees to move good in and out of the city, provided one does not use the smuggling tunnels controlled by ghouls and the organized crime community, but once inside one will find it incredibly easy to buy and sell almost anything without attracting too much attention. Jerusalem's black market is famous for being able to supply literally anything.)
The title of King of Jerusalem has been claimed almost a hundred times over the years. Some of them ruled for only a few weeks, others founded dynasties that lasted centuries. Sometimes they are raised up in times of crisis by agreement of the city's power blocs, other times they ride into power on a wave of popular approval. Others are conquerors, who enter the city and crown themselves stewards of the City of God, and stay a while, intending to make the city their own.
There have been highborn kings and lowborn kings. There have been many men, a few woman, and one who claimed to be both. Most have been humans, but there have also been Djinn, Nephilim, and even a single succubus. Many cambions have risen to power, with the general populace none the wiser. Ghouls have "ruled" the city three times, when after horrific massacres they came boiling onto the surface to claim the bodies and refused to go back down below, a ghoul warlord each time crowning himself king of the overcity until being slain by a hero.
Some kings were good, some were bad, some were saints, some were madmen. There've been Christian, Muslim, and Jewish rulers. Some ruled by law, some at the grace of God, others by the sword, a few were even skilled magicians.
For you see, Jerusalem is no mere city. It is not the jewel in a crown of a potential king, it
is the crown, the ultimate prize for any would-be emperor. The title of King of Jerusalem stands first in status and respect the world over. Any empire will naturally have Jerusalem as its focal point. It is the City of God, the city all other cities strive to be like.