Fifth Battle of BeleriandFifth Battle of Beleriand (472 B.C.) - Also known as Nírnaeth Arnoediad (The Battle of Unnumbered Tears).  It was the final battle between Morgoth and the Elves, and Morgoth's victory prompted the Valar to finally intervene (see War of Wrath).

 

"Then in the plain of Anfauglith, on the fourth day of the war, there began Nírnaeth Arnoediad, Unnumbered Tears, for no song or tail can contain all its grief.  The host of Fingon retreated over the sands, and Haldir lord of the Haladin was slain in the rearguard; with him fell most of the Men of Brethil, and came never back the their woods." ~The Silmarillion, chap. 20 (Of the Fifth Battle)