Battle of DagorladBattle of Dagorlad (3434 S.A.) - The battle near the Black Gate of Mordor at the end of the Second Age between the Last Alliance of Elves & Men and the forces of Sauron.  It was the prelude to the Siege of Barad-dûr in the Black Land.

 

"From Imladris they crossed the Misty Mountains by many passes and marched down the River Anduin, and so came at last upon the host of Sauron on Dagorlad, the Battle Plain, which lies before the gate of the Black Land.  All living things were divided in that day, and some of every kind, even of beasts and birds, were found in either host, save the Elves only.  They alone were undivided and followed Gil-galad.  Of the Dwarves few fought upon either side; but the kindred of Durin of Moria fought against Sauron." ~The Silmarillion (Of the Rings of Power and the Third Age)