who are the nazgul?

[Alfirin]

Originally Posted by Ivriniel

We really don't know what 'witch' powers of 'sorcery' the Witchking held. Or whether or not she? studied sorcery, or dabbled, before changing genders. Perhaps Sauron was just having a cosmic joke, and really liked Numenor.

About the only we one we know of is that the WK does know necromancy, since If I recall, it is the WK who orignally summoned the spirits who became the Barrow Wights.
I also want to make note that it is written that Sauron granted special powers but NOT rings to two chiefs of the Haradrim (presumably, these powers might be similar to those provided to the Mouth of Sauron) which seems to indicate Sauron may have been low to out of rings before coming among the Haradrim, and so there may NOT be Haradrim amoung the Nazgul's numbers. Though there still may, it sort of depends on how unfied the Haradrim are (if the men of the Harads are made up mostly of small fractios tribes, the concept of bestowing rings on lords so great they basically ruled (or with the ring, could rule) the whole area may not have been feasible.) The problem here is, not only do we not know the patrimony of most of the Nazgul, we also are not aware of the criterion Sauron used in selecting worthy candidates. As indicated above, I, tend to work from the assumption of "Distribute the rings in such a manner as to bring the maxium number of men/amount of territory under thier, and therfore my, control". but that is just how I'd do it.