What is the name of the battle where Rohan comes to Gondor's aid?
The battle where Rohan comes to Gondor's aid is the Battle of the Pelennor Fields. This is a key battle outside the city of Minas Tirith in "The Return of the King." The Riders of Rohan, led by King Théoden, play a crucial role in turning the tide of the battle against the forces of Mordor.