Bór, along with his three sons, Borlad, Borlach, and Borthand, were followers of Maedhros and Maglor, two of the seven sons of Fëanor.

Bór was a chieftain of the Easterlings who came into Beleriand with the rest of his people the year after the Battle of Sudden Flame. He was at first secretly allied with Morgoth, but turned away from him, instead serving the sons of Fëanor only.

Bór's means of death is not known.