Dunlendings

In the Second Age of Sun, before the Dunedain came to Middle-earth and made the kingdoms of Gondor and Arnor, there lived a tall dark-haired people in the fertile valleys below the White Mountains. For many centuries, it is said , they developed a civilization apart from other people and built many great fortresses of stone. No history tells of the fate of these Men of the White Mountains, yet they vanished and only those descendants named Dunlendings remained in their lands.
Long before the Dunedain made the kingdoms of Arnor and Gondor, Dunlending power had dwindled. The people had become divided. Those who remained in Dunharrow became allies of the Men of Gondor; others had wandered North and settled peaceably in the land of Bree. Yet most of the Dunlendings had retreated to the hills and plains of Dunland and had become a tribal herding people. Though they kept their language and remained fierce warriors, they became a barbaric folk.

In the twenty-sixth century of the Third Age the Men of Gondor granted the Rohirrim a province called Calenardhon but the Dunlendings considered it theirs by right. So these two peoples grew to hate one another, and in the year 2758 a Dunlending named Wulf led a great invasion of his people against the Rohirrim and was victorious. But this was at great cost, for in the next year the Rohirrim arose and drove the Dunlendings back into the hills, and Wulf himself was slain.
So it was that for nearly three centuries the Dunlendings remained in the hill lands and left the fertile valleys to the Rohirrim. Yet they did not forget their hurt, and the tall, dark Men of Dunland made an evil pact with the rebel Wizard Saruman who had brought vast numbers of the Great Orcs called Uruk-hai into Isengard. And it is recorded that by some evil act of sorcery the Dunlendings were bred with the Uruk-hai, and evil offspring called Half-orcs were the result of this union. Half-orcs were black, lynx-eyed Men with evil Orkish features; combined with the Dunlendings and Great Orcs, the Half-orcs made a hug army of terrifying strength.