Originally Posted by
The Madgod
Morzath's reason to create an empire:
The Lich King is dead, and the Banshee Queen is restless. Morzath remembered the last words of Illidan Stormrage, recorded by a scribe who went with the band of heroes who killed him, "The huntress is nothing without the hunt". With the Lich King dead, Morzath is worried that Sylvanas will become a lesser being, and a lesser being in charge of thousands would mean terrible things. She would resort to that which the Lich King did; rob the forsaken of their identity and independence.
Finding many who agreed with him, he created a small army, full of Forsaken Shock Troopers. Even the Dark Coven, a group of warlocks and necromancers of all races, has given him their support. With this army, Lordaeron would be his for the taking. The elves of Silvermoon would ally with him, and eventually, he would hope to take over the entirety of the Eastern Kingdoms, creating an empire of prosperity and arcane knowledge. With the Sunwell, he might even find a way to restore himself and his undead bretheren into life, possibly an eternal one.
However, Morzath needed certain raw materials to accomplish this. Having broughten some of the stuff back from Northrend, he knew of the power and use of pyrite. Though he had enough to begin his venture, and secure the undercity, he would require much more to lay seige to Ironforge and Stormwind. When he heard of the deposits in tanaris, he brought a portion of his followers to the desert, in hopes of securing the precious material for himself, or at the least, receiving a portion of the stuff.