What happens when Tiamat DOES rise?

[Ballestra]

I'm DM'ing a group that's been running a (heavily) modified version of Rise of Tiamat and, as events unfolded in the final encounter, Tiamat did, in fact, rise into the world hotly intent on setting up her reign on the Material Plane.

The PCs managed to escape with their lives, and now we're interested in playing the insurgency-to-the-evil-empire campaign. My question to the hivemind:

What would Tiamat's reign look like? How would evil dragons rule? In our world, Bahamut has already been neutralized...for now.

What are your thoughts?

[Blake Hannon]

The world is divided up into petty kingdoms ruled by draconic tyrants. Humanoid lives are thrown away without care or regard in the dragons' endless power games.

Think of a really cynical take on the middle ages, only with the royalty being literally a different species, and a psychopathic one at that.

[Rogem]

The world is divided up into petty kingdoms ruled by draconic tyrants. Humanoid lives are thrown away without care or regard in the dragons' endless power games.

Think of a really cynical take on the middle ages, only with the royalty being literally a different species, and a psychopathic one at that.

Game of (Dragon) Thrones, in short.

[Ballestra]

Think of a really cynical take on the middle ages, only with the royalty being literally a different species, and a psychopathic one at that.

Sure, but is it reasonable to assume that the goons/muscle for the day-to-day enforcement come from the evil or bad sections of the regular humanoid races, or would some monstrous race be more believable for this? E.g., would elves serve an evil dragon? What would chase dwarves out of their mines to cough up their treasure? Or would they flee deeper underground?

And because Tiamat is the embodiment of chaos, would there be any recognizable feudal structure or organized...anything?

[Admiral Squish]

Lolth is a chaotic goddess, but her city is crazy-organized. I think there has to be some degree of order in order for there to be a government, but the rule of thumb for chaotic evil leadership is that nobody is 'safe'. Like, you can't lay back and do nothing, you have to constantly struggle to maintain your position, and struggle harder if you want to get to the top.
By that metric, I would say you'd want a very loosely-organized system. Dragons are the kings, laying claim to whatever regions they can control, competing with each other wither directly or indirectly to get more and more territory/wealth/power. Loyal kobold worshipers are under their direct control, acting as armies and overseers, and everything else is somewhere between 'food' 'toy' and 'slave'. Prove your loyalty and you can get promoted to 'servant', but ultimately, you can always be demoted to 'snack' if you disobey. Who exactly decides to join up with the dragon overlords is a mostly personal question.
I could imagine dwarves pulling a classic 'seal the gates and wait it out' move, but with kobolds emboldened and motivated by dragon lords, they'll probably be facing increasing pressure from below.