@lithium Yes ... but it never really has the feel of an ancient and glorious empire. It's one guy's invention and he's in charge for almost all of its history. Amber feels more like a very stretched out version of Henry VIII's England than it does like the eastern Roman Empire at or after its apogee. You'd need to go far enough forward that not only is Oberon a semi-mythical figure, but even his sons and daughters have been gone for long enough that people argue over what they did or didn't do like academics discussing whether Shakespeare was really Anglican or a secret Catholic.
Or you could go completely the other way, and have an Amber that's basically that of the books, only all of Oberon's still-living children have up and vanished one bright morning, and it's up to the players to figure out why. Or to not figure out why, and instead get straight to the important business of who's going to sit in the big chair next.
Or you could do an Amber that shares only the basic concept of the Pattern and Shadow with the original, and comes with a whole new geography, history, royal family, etc. (I'm partial to an Amber City that's vaguely Venetian, so people can get thrown into canals at the end of duels, or wax anxious about how hard it's going to be to walk the Pattern if the water's four inches deep in its chamber.) To me this is kind of the most fun direction, but it's also the hardest creative job, and it asks a lot of the players in terms of unlearning what they already know and learning different things.
I don't really have a strong attachment to a particular setting, or I'd probably be working on a game -- I just know that when I think about the standard Amber game approach of "let's throw a dart at the known timeline of Amber history and set our game there; now, everyone get your feature apps ready, aaaaaand GO!" I feel a tremendous disinterest.