The hills east of the Lonely Mountain, rich in iron, and the stronghold of the Dwarves of Dáin Ironfoot's line. From them Dáin marched with five hundred mailed Dwarves to Erebor's aid in the Battle of Five Armies, and there took up the kingship after Thorin's death. The Iron Hills' iron-shod warriors were the backbone of the North's defense in the War of the Ring.