Lóni was part of Balin's Colony to reclaim Moria. Their mission at first seemed successful, and Balin went so far as to claim the title Lord of Moria. Over a period of a few years, though, it became clear that the Dwarves were not as secure as they had hoped in their ancient citadel, and at last the Orcs came in force to reclaim it. The Bridge of Khazad-dûm was captured, leaving the Dwarves trapped in the Second Hall. There was a mighty battle in the Hall, and many Dwarves fell, including Lóni and his companions Frár and Náli.