Along ancient Saharan trade routes, 1,300 years of shared history that have mingled the faiths, cultures and skin tones of Arabs and Africans has left another, more vicious legacy: Arab-African slavery that has endured as long as the two peoples have been together, leaving black Africans fighting perceptions of themselves as lesser beings, and of Arabs as the civilizing, conquering force. Today, the old roles are playing out at their most extreme in Sudan's Darfur region.