Long before their reign, the ancestors of men rallied on Midworld against the children of Asag, to make the earth habitable. For a thousand years, they were joined in peace by the power of the High People.
The Lords of Men refer to many different kinds of sovereigns from many different realms. Their eventual Alliance, which was brokered by a Justicar of the High People, became a sacred oath forged in the Castle Moongarm that prevented all-out war between them over the territories of Midworld.