Of the three lands surrounding Tolkien's narrative, Khand is the least talked about. At one point in Gondor's earlier history, they are invaded by a group of Easterlings called the Wainriders. During the invasion, the nomadic army moves through the territory of Khand and the locals seem to join them in their attack.
Also, in "The Return of the King" we hear that a group of soldiers called "Variags from Khand" fight at the Battle of the Pelennor Fields. Apart from these two tidbits, though, there is very little out there regarding what this third strange land southeast of Mordor was like — other than the fact that it, too, appears to have been thoroughly subdued by Sauron for large chunks of its history.
After the War of the Ring, we get a little more information about how at least two of these three peripheral kingdoms get along — and it's a bit of a mixed bag, to be honest. In "The Return of the King," it explains that, after he becomes king, Aragorn "pardoned the Easterlings that had given themselves up, and sent them away free, and he made peace with the people of Harad."
Sounds good, right? It turns out that it's not all sunshine and roses after the Ring is destroyed. Our buddy Aragorn, who rules for over a century, eventually quarrels with his neighbors for unknown reasons in the years that follow. In fact, both he and Éomer go to war together, leading their armies "beyond the Sea of Rhûn" and to "the far fields of the South."
While there isn't much out there beyond these basic elements, there's no doubt that Rhûn, Khand, and Harad all represent rich, unexplored areas of Tolkien's mythology. If Amazon or any other studio decides to weave them into future Middle-earth storytelling, it could add a fascinatingly diverse new perspective to the Middle-earth that we all know and love so well.
