|First Battle of Beleriand|
|Location||East and West Beleriand|
|Result||Weak Elven victory in the East,|
undecided in the West
|Participants||Thingol, Denethor†, Círdan, Morgoth|
In J. R. R. Tolkien's fictional Middle-earth, the First Battle of Beleriand is the first battle of the Wars of Beleriand, fought by the Sindarin Elves, led by Elu Thingol, King of Doriath and Lord of Beleriand, against the armies of Morgoth, the Great Enemy, the Dark Lord.
Morgoth, escaping Valinor, arrives in Middle-earth, and occupies his old fortress of Angband under the mountains of Thangorodrim while the Noldor pursuing him still toil through Araman. His servants, Sauron and Gothmog have long been breeding Orcs as warriors for his armies.
Morgoth decides to move quickly to conquer Beleriand and he sends out his armies. Two Orc-hosts advance south from Angband. One moves west through the vale of the River Sirion and the second east between the rivers Celon and Gelion. The Orcs make camps on the Estolad plain in the east and the Talath plain in the west and they harry the lands about. In this first battle the Sindar, their allies the Green Elves, the Falathrim, and the Dwarves meet the forces of the Dark Lord in the open field.
In East Beleriand, Denethor lord of the Nandor, or Green Elves, fights the Eastern Orc-host on Amon Ereb, an isolated hill south and east of Doriath. Only lightly armed, they take heavy casualties. Thingol with the army of Doriath arrives to save the Nandor from annihilation but Denethor falls before Thingol can save him. The Orcs are defeated and those that survive the battle are slain in their rout by the Dwarves of Mount Dolmed.
In the west, the Elves of the Falas under their Lord Círdan, cut off from Thingol, meet the western host, but they are defeated, and retreat to their havens of Eglarest and Brithombar. These cities are besieged, and Doriath is unable to gather a strong enough force to send aid. The sieges of the havens of Falas are only lifted when the Orcs withdraw to reinforce the assault by a third Orc-host on the Noldor Elves under Fëanor, new come and encamped in Mithrim.
The First Battle is the only one of the five great battles where the Sindar of Doriath take the primary role. After the First Battle Doriath is protected by the magical Lest Melian, the Girdle of Melian. Its mists and shadowy mazes hide entry to Doriath and Thingol takes a defensive stance behind it. The death of Denethor, king of the Green Elves, in this battle leads the Elves of Ossiriand to never again name a king or participate in the wars between the other Elves and Morgoth until the Fifth Battle, Nírnaeth Arnoediad.
- This battle has no elven name and is only known as the First Battle as a proper name. In The History of Middle-earth, Vol. IV and V., the words are capitalized and the battle is what later becomes the Second Battle in the Silmarillion and the Grey Annals in HoMe XI, there lower case is used for the first but appears an editorial oversight carried over from Grey Annals to The Silmarillion.