Power of the North

Melkor was one of the primordial Powers who had played a part in the shaping of Arda, and descended into the world after its creation. From the most ancient times, this Dark Lord had been associated with the far northern parts of Middle-earth. His first great fortress was named Utumno, standing on the cold northern shores of the Great Lands, and protected to the south by the curve of the Iron Mountains. Melkor dwelt within that great fortress until the time of the Battle of the Powers, when Utumno fell to the Valar, and Melkor himself was taken as prisoner back to the Valinor.

Three ages later, the Captivity of Melkor came to an end when the Valar chose to release him from his imprisonment, but he quickly turned against his former captors. He destroyed the Two Trees that gave Light to the realm of the Valar and stole the Silmarils that held the last vestige of that Light, before escaping back into Middle-earth. There, he took refuge in an outlying fortress of old Utumno, a far northern stronghold named Angband.

Soon afterward, Fëanor led a great part of the Noldor back into Middle-earth, and they made war against Melkor (whom Fëanor had renamed Morgoth the Black Foe). These Elves settled lands that lay across Beleriand and its neighbouring regions, far to the southward of Angband, and so to the Elves and their allies the Edain, Melkor Morgoth was known as the Power of the North.

Morgoth continued to hold Angband in the North throughout the remaining centuries of the First Age, and in the last years of that Age he gained many victories against the Elves. It was only in the War of Wrath, in which the Valar themselves challenged Morgoth as they had in ancient times, that the Dark Lord was defeated. He was expelled from the world, and the fortress of the Power of the North was drowned beneath the waves of the Great Sea.