The Armies of the West had decided to march to the Black Gate for a final encounter with Sauron. Aragorn wanted to make Sauron think that he had the One Ring. That way, Frodo Baggins and Samwise Gamgee could destroy the Ring inside Mount Doom. The Armies of Gondor and Rohan had about 7,000 men.
As the Armies of the West were marching through the Gondor province of Ithilien, they were set upon by Easterlings and Haradrim also known as Southrons. The Gondor and Rohirrim troops fended of the attack with no losses. The Easterlings and Haradrim retreated. The Armies of the West won the battle.