Nyx was founded when a mysterious lady of shadows appeared before Wakanda Tallbear, a noble druidess, and tasked her with leading the most heroic, chivalrous and mighty members of the Horde. This happened not long after the Forsaken were admitted into the Horde.

Over the years Lady Nyx, and her chosen Leaders. created her tribe to be stronger, mightier and the most noble guild in the Horde. Their conquests have become the stuff of legends.
Lady Sylvanas bequeathed upon Nyx charge over her very own Twilight Umbrage – a guild of heros devoted to fighting the Old Gods and their followers the Twilight’s Hammer cult, and by extension due to the link with Sargeras behind the formation of the Twilight’s Hammer cult, Sargeras and the Shadow Council.
Thrall gave the Nyx a building in Orgrimmar to use as their Library.