Fluffyhotep
Watchdog
This is a good point. Something like the Aksumite Empire, contemporaneous with the Romans, would be an excellent fantasy setting.
Palaces, temples, centre of east/west trade, warrior queens and The Queen of Sheba, mythological resting place of the Ark of the Covenant - and when was the last time you saw it represented anywhere?
Not really, it wasn't exactly a grade A civilization back then - very little to no monumental architecture, no cool armour like the Romans and Persians.
Nubia would be a safer bet, with its strong Egyptian influences.
In general though, more exotic settings usually have a very hard time selling to a wide audience. It would have to be really, really good and have a really, really smooth introduction to its story and setting. I don't think it's impossible, but it's way more difficult than the same old quasi-medieval pseudo-British stuff.