There have been two or three realms in the Rettleville area, but they weren't really resurrections of old realms. Same with D'Hara being in the same place as Shadovar. Same location, completely different realm.
D'Hara was formed by Shadovarians. Mind you, ruling elites came and went in waves. Personally, I consider the D'Hara/Shadovar conflict to be nothing else than a civil war, as it was due to a split within a ruling gang that caused a lot of bad blood and bitter fighting. Both parties had come to the lands hand in hand, as far as I know. It's the impression I got from them in the days, at least. I tend to consider Shadovar as being part of D'Hara's history, though I think I'm the only one left in the realm that actually once bore the Shadovarian flag.
