Far Harad, a part of the larger region known as Harad, was a name used in Northwestern Middle-earth for a distant, unknown land far to the south of Gondor. The name simply means the Far South (Sindarin harad, "south"), as opposed to Near Harad, the more familiar southern lands.
Some of the people of Far Harad travelled north at the time of the War of the Ring, and fought on the side of Sauron at the Battle of the Pelennor Fields. These warriors (which were described as Half-trolls) had black skin, unlike those of Near Harad (said to be brown skinned)[source?].