Dreadlords were men and women able to channel the One Power that went to the Shadow during the Trolloc Wars. They acted as battle commanders, overlords of the Trolloc forces, above the Myrddraal in chain of command. Even when victory appeared all but at hand, the Dreadlords never assumed the title of Chosen, for fear that when the true Chosen were freed from their prison in Shayol Ghul they would object to lesser channelers using the title.
Although this generation of Dreadlords were entirely wiped out, many Darkfriends in the New Era expect to become the new Dreadlords after Tarmon Gai'don comes. Some already use this title, although Dreadlord females retain the Black Ajah honorific. A fear amongst many of those able to channel the One Power is that they will be turned to the Shadow against their will by an unholy union of thirteen channelers linked through thirteen Myrddraal. It is uncertain if there is anyone alive who has been forced to the Shadow against their will this way, although it is a possibility (if, perhaps, a slim one) that at least some of the current crop of Black Ajah were turned to the Shadow by this method.
The end of the Last Battle finds the majority of Dreadlords dead or captured.