The Balrogs of Morgoth were fiery Maiar, primordial spirits that helped shape the World in the beginning. Balrogs took the form of fire engulfed humanoid creatures. They often carried weapons which were also aflame. In ancient times, the Balrogs were persuaded by Melkor to join his cause to rule Middle Earth. They were exceptional powerful. Durin’s Bane, the Balrog who drove away the Dwarves of Moria from their ancient fort, was encountered by the Fellowship of the Ring when they passed through Moria during the War of the Rings. After a fearsome duel, the Balrog was eventually slain by Gandalf the Grey.