Ah the Dunmer... Closest Mer to my heart...
Anyway, the Redguard are decended from the inhabitants of Yogouda (I'm probably spelling that wrong) and though they have interbred with humans. The Crowns, whats left of them anyway, still maintain laregly pure bloodlines, and look less human than the Mer. In fact, their supposed to have metalic skin... Anyway, the overwhelming majority of Redguards are a hybrid race, and while classified as men they are not true men in the same way the Nords and Imperials are. They are closer to the Bretons, who are in fact a cross between Men and Mer.
Their exact reasons for seperating are open for debate as well. Worship of Talos wasn't really that overwheliming in Hammerfell, but they do not take backing down lightly. As such, i view the signing of the Concordant, rather than the specifics of it, to be the reason the Redguard seperated.
Edited by Lachdonin, 01 December 2011 - 11:45 PM.