A Marshal of the Riddermark who commanded the muster of Edoras in the War of the Ring. He led his eored in the night-ride to Gondor, where the Wild Men of the woods guided the host past the blocked road — and it was in Elfhelm's company that a small soldier called Dernhelm rode, carrying a hobbit. Tolkien hints in the quietest way that Elfhelm knew exactly who Dernhelm was and chose to see nothing. At the Pelennor he led the right wing against the siege-engines, and afterward defended Anorien against the enemy's remnant while the host marched on the Black Gate. Under King Eomer he became Marshal of the East-mark.