Before that, in the First Age, the Atani from whom the Haradrim descended were known as Black Men.
During the Second Age the Men of Númenor built a great city in the firth of Umbar, a vast natural harbour on the southern shores of the Bay of Belfalas, eventually turning the city into a fortified citadel from whose gates the Men of Númenor could levy great tributes upon many of the tribes of Harad.
At the time of the War of the Ring, the Southrons were in league with Sauron and fought alongside his orc army, riding atop gigantic, elephant-like Mûmakil. Once Sauron was destroyed, the Southrons joined forces with the Easterlings and Variags and their Kings started war on King Elessar, as well as off-continent enemies from since before the First Age.
For many years, the Haradrim were the greatest enemy of Gondor. Several times, they invaded the north. Finally, the Men of Gondor were able to capture Harad, though it was later freed. During the War of the Ring the Haradrim were allied with Sauron. A Haradrim warrior wounded Faramir. At the Battle of the Pelennor Fields the 18,000 Haradrim, mostly mounted on the mumakil, were a great threat to the Rohirrim that had come to aid the people of Minas Tirith. At the Battle of the Pelennor Fields a chieftain, bearing the standard of a black serpent on a scarlet field, led the Haradrim cavalry. King Théoden of Rohan slew this Haradrim leader in single combat.
Their appearance is somewhat ambiguous, but The Two Towers gives a detailed description of a slain Haradrim warrior that Frodo and Sam encounter. He is described as having swarthy skin and black hair that is braided with gold. He wore a scarlet tunic, as did the other warriors, and a gold collar. His weapon and armour are simply described as a sword and a corslet of brazen plate.
The lands of the Haradrim lie to the south of Gondor past the river Poros. These hardy people lived in one of the harshest environments in Middle-earth. In the land south of Gondor, the sun beat down unrelentingly, cooking much of Harad's Great Plains into desert . Many tribes of Haradrim lived a nomadic existence , walking from one oasis to another in search of precious water and food, and here they would gather kine and other beasts .
Farther south in Far Harad there were said to be dense jungles, in which was found a bamboo-like material  they used for weapons, armor, utensils and construction; the desert lands of Harad yielded few trees, so bamboo was used in place of wood. Extreme poverty, a by-product of their nomadic existence , was the main factor in the Haradrim's allegiance to the dark lord Sauron, who offered them wealth and water for their people . Haradrim towns and cities presumably existed nearer to the coast where fish and sea trade allowed a more urban existence, as well as a haven for pirates and corsairs.
The Haradrim are said to be skilled archers and horsemen. In battle, they usually drove their Mûmakil into the enemy's ranks, causing terror and panic; with their foes in disarray, the Haradrim then flung spears and fired arrows down upon them from the covered canvas frame atop the mûmak. Their bows, possibly of compound design, were made out of composite materials like antlers and wood and used bamboo arrows from leather or bamboo quivers . Usually this would be enough to rout their foe, but if not the main host charged in behind the great beasts, using their spears, swords and bows with bloodthirsty zeal. In The Battle of the Pelennor Fields, the Haradrim use Mûmakil to rout the forces of Rohan . As the mûmakil were accustomed to and effective against cavalry , this rout was initially successful . However, strategic use of bows and spears and the arrival of reinforcements (book) or Army of the Dead (movie) summoned by Aragorn eventually destroy the Haradrim's forces at Pelennor.
Harad was a region divided into many tribes , and as such was ruled by many chiefs and warlords. On occasion great kings would rise, ruling over much territory. However, few were regarded as true leaders of Harad.
Future of Harad
Much of Harad's impressive army was wiped out on the expanses of Pelennor Fields, during the Battle of the Pelennor Fields, in which Harad's forces amassed one of the greatest legions their land had ever seen, containing many thousands of men, all armed with bows, spears or the reins of the Mumakil. With Sauron defeated, many Harad peoples sent emissaries to the court of King Aragorn, and peace talks began; however, many other Haradrim tribes continued hostility with Gondor.
Portrayal in adaptations
The Lord of the Rings film trilogy
In Peter Jackson's The Lord of the Rings film trilogy, the Haradrim are inspired by Aztecs and Kiribati tribes, according to the ROTK DVD's Weta Workshop documentary. The apparent leader of the Haradrim force is killed in the film not by Théoden, but by Éomer.
- They appears as toys in The Lord of the Rings Trading Card Game and The Lord of the Rings: The Battle for Middle-earth II.
- In The Lord of the Rings: War of the Ring, they appears as "Haradrim Slayers".
- The Lord of the Rings Strategy Battle Game has given the unnamed Haradrim leader Théoden kills the name Suladân and the title "Serpent Lord", and its players often refer to him as the "Black Serpent" after his standard. Some are assassins called "hasharin"; there are also characters like "The Golden King" and "Dalamyr", and place-names such as "Kârna", "Abrakân", "Badharkân", "Hidâr", "Nâfarat", and "Dhâran-sar" appear.
The People of Middle-earth