There's quite a bit of funky racism going on in the Reach, which I found pretty interesting. Basically, it seems like the Breton-ish natives of the Reach have been or are being systematically displaced by Nord conquerors, mainly led by the Silver-blood family (who, if Ulfric wins the Civil War, will take over as Jarls of the Reach).
It makes me a bit frustrated that you can't actually join the Forsworn (basically the Breton resistance), since they're quite clearly the good guys in the conflict (for a given value of good).
Though there seems to be some in-story confusion regarding whether or not the natives of the Reach are Bretons. The castle chef at Markarth will say something to the effect of "I'm a Breton, not a Reachman. I came here from High Rock", while one of the in-game books (I think Madmen of the Reach) notes that the Bretons and the Reachmen have some distinct similarities.