Empire of Arathor

From wow.incgamers.com

Long ago, the humans of Azeroth lived a nomadic, tribal lifestyle. Eventually one tribe, the Arathi, grew to dominance and saw the benefit of uniting the other clans, thus forming the first human nation, 2,800 years before the Dark Portal was opened.

The High Elves of Quel'thalas sought the aid of Arathor in combating their Troll threat, and in exchange for the knowledge of how to use magic the Empire of Arathor consented.

Eventually the Empire grew too large to sustain itself and 1,200 years before the Dark Portal was opened, after 1,600 years of power, it fragmented into seven different, individual kingdoms: Alterac, Azeroth (to be the Kingdom of Stormwind), Gilneas, Hillsbrad, Kul Tiras, Lordaeron and Stromgarde.

The last known heir of the kings of Arathor was Anduin Lothar, who was killed by Orgrim Doomhammer