During the War of the Ring, Caladhir joined in the ranks of the Royal Lothlórien Army under the command of Haldir. There, he along with 1,200 elven soldiers arrive to Helm's Deep to participate in fighting Saruman's army. Caladhir fought long and hard against the Uruk-hai and killed nearly hundreds of them when the wall was blown up. Caladhir avoided the explosion and continued to fight and prevent the Uruk-hai breaching. When Théoden, King of Rohan, called for everyone to retreat, Caladhir did so and helped Legolas pick up Gimli, who was fighting very hard, and dragged him back to the keep. Caladhir survived the battle and would later travel to the Undying Lands at the start of the Fourth Age.