The fourth battle of the Wars of Beleriand and the most disastrous for the Noldor. The name means Battle of the Unnumbered Tears in Sindarin.

The battle was initiated by the sons of Feanor in an attempt to reclaim the Silmarils from Morgoth and to defeat the evil forces which were steadily creeping into Beleriand from Angband. The forces sent against Morgoth were formidable: the host of the sons of Feanor was joined by Turgon's forces from Mithrim, humans from Ossiriand, Hithlum and Brethil and small companies from elsewhere, including a company led by Gwindor from Nargothrond. Turgon also sent a host forth from Gondolin after hearing of the situation. However, the elves were weakened by the absence of larger contingents from Doriath and Nargothrond, as a result of preceding events in which Elwe of Doriath had obtained a Silmaril and in which the sons of Feanor had made a bid for power in Nargothrond.

The armies were split into two forces. The eastern force, led by Maedhros, was to draw Morgoth's forces out, after which the western force, led by Fingon