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. For centuries, the Haradrim were the greatest enemy to Gondor and Harondor. The Haradrim have planned a number of sieges to invade the north, but the Gondorians were able to drive them away. The Chieftains of the Haradrim grew reckless and never gave up.
At the time of the War of the Ring, the ancient enemies joined forces with the dark lord Sauron and fought alongside his orc army, riding atop gigantic, elephant-like Mûmakil. The Haradrim in Gorbon were also allies to Sauron. During the Battle of Pelennor Fields, more than 2000 Haradrim warriors and archers were riding atop 50 Mûmakil, along with 100,000 Easterlings marching behind, attacked the Watchers Army and Rohirrim Army.
The Haradrim are described as been proud and warlike. They most likely resemble Arabs by their clothing and color of skin.