|Fate||Attending Aragorn's coronation|
- —Haethen ordering his archers to open fire on the Uruk-hai during the Battle of Helm's Deep
During the War of the Ring, Haethen had fought against the enemies of Isengard that were trying to weaken Rohan's defenses. While some of the villagers from the Westfold had survived and the rest perished, Haethen was among an infantry of Rohirrim soldiers that fought against the Dunlendings of Dunland to prevent such atrocity from happening, but that was when he lost an eye. Despite losing an eye, Haethen continued to serve in his majesty's army while he traveled to the old fortress of Helm's Deep. When word was reached from Aragorn that Saruman unleashed an army of 10,000 Uruk-hai to annihilate the people of Rohan, Haethen volunteered to serve in the defense against the enemy. With the support of a battalion of Elves of Lothlórien, Haethen took command of a number of archers and ordered them to open fire upon the enemy that was charging towards the Hornburg and the Deeping Wall.
Despite the heavy casualties, Haethen was among the defenders that survived the battle of Helm's Deep and returned to Edoras to celebrate and honor those that gave their lives for defending Rohan and its people from suffering at the hands of Saruman. When Sauron was preparing to launch his desperate attack on Minas Tirith, Haethen was among those that traveled to Dunharrow and fought in the Battle of Pelennor Fields until the Rohirrim was reinforced by the Army of the Dead. With King Théoden's death, Haethen pledged his loyalty to Éomer Éadig since he was now the king's rightful heir to Rohan's throne. Gathering hundreds of survivors that were gravily wounded from the battle, Haethen traveled to the House of Healing where he provided his assistance in healing some of his men that he care about. Later on, Haethen accompanied a company of Gondorian and Rohirrim soldiers towards the Black Gate of Mordor and give Frodo Baggins a chance to destroy the One Ring. With the One Ring destroyed, resulting Sauron's death, Haethen attended the coronation where Aragorn became the King of Gondor and Arnor, and a new age had begun for the world of Arda.