A royal-blooded warrior-Dwarf of Erebor, Frérin was Thrain II's younger son. Brother to Thorin Oakenshield and Dís, Frérin escaped Erebor with his family in T.A. 2770 during the attack by Smaug the Golden. Thereafter he, like so many of his kind, lived in heart-rending exile. At the battle of Azanulbizar (in T.A. 2799), Frérin was slain beside Fundin as they led the first assault upon the Orcs inhabiting Moria.