A term used by the Vala Ulmo to describe the evil power of Morgoth in Angband, to the north of Beleriand. It seems to apply to more than simply Morgoth himself; Ulmo used it in the specific context of the defilement of Eithel Sirion, which caused his own power (running through the waters of the river) to diminish. This defilement was doubtless Morgoth's intent (as was the defilement of Eithel Ivrin by Glaurung) but it was clearly not a direct action of Morgoth himself. Hence 'Evil of the North' appears to be a reference to the evil acts and followers of the Dark Lord, as much as to Morgoth himself.