It's a beautiful map! The concept sounds good, too - although you should be careful: 1200 years is a lot longer than it seems (if, for example, you take the fall of rome to be c. 500 AD, then 1200 years later would be 1700. A lot changed). But that's all I have to complain about, and that's an amazing accomplishment.

The mountains do look very natural; I think it contributed a bit to Kristoni's perception of repetition. Because the northern mountains all seem to...drip downward, it sort of looks like a skeleton of repeating structures, like a very, very long ribcage.

This sounds like a great campaign setting, I'll be looking forward to seeing your other maps of it and reading more about it.