Astravelle

The largest city in the world. From things I've heard, the most decadent one as well.

The Ardenian Empire is most proud of three things: its long history, its vast lands and its ubroken lineage of Emperors and Empresses. The capital city of Astravelle embodies all three. Centuries of history left many scars and marks on the city, as did numerous various communities who settled in it over this time. However, Astravelle - ancient for Starlit Basin - has always been the seat of imperial family first and foremost. And, for most of his history, a golden cage.
After all, it has always been more of a symbol than a defensible stronghold. There is even an Ardenian saying "he who controls Astravelle", meaning a person with real power. It is thus that many people are constantly on the lookout for any news from the capital, taking it to represent their own futures. When Astravelle flourishes, all will be good. When its suffers from plague or burns in flames, so will the empire. Not sure I agree on the whole "omen" aspect of it, but you cannot deny the logic.

Demographics

I doubt even the emperor himself knows how many people live in Astravelle. Hundreds of thousands, that much I can tell. The city population has really skyrocketed in the past decades, which I believe to be mostly due to the growing power of the imperial family. Old nobility is forced to spend more and more time in the capital to stay relevant, and that brings in servants and craftsmen as well. More soldiers and bureaucrats too, meant to keep the nobles and each other in check.

Districts

If you ever visited Astravelle, you must have noticed the very clear lines of division between different communities and social classes within the city. So much that it is more akin to a group of different settlements rather than one large city. Most ironic of all is the fate of the Starlit Basin itself, the old city district. Located near the middle of the city and once home to almighty emperors, it has long fallen into disrepair and became the last refuge of poor and desperate.

History

According to official history, Astravelle was one of the first Kosari settlements and birthplace of the Ardenian Empire. Sadly we not have any other contemporary sources speaking of Astravelle, so it is hard to tell if the city was actually too minor to be mentioned at first or records of it simply did not survive through the ages. What we know is that by that time of the imperial rapid expansion throughout the continent the imperial family had already lived in Astravelle, as evidenced by witnesses from among the conquered communities.
Of course, Astravelle back then and nowadays have near nothing in common. After all, the city was completely lost in the flames of civil wars at least four times. Its location, architecture, traditions and culture - all has changed many times over. It is after one of such complete destructions that the imperial family chose to abandon the old indefensible area in the basin and move onto higher grounds. Not that it helped them much, as whoever tried to fortify Astravelle has always ended mysteriously dying or being deposed as tyrant.