War of the Last Alliance

The War of the Last Alliance was brought by the Last Alliance of Elves and Men upon the Dark Lord Sauron in response to his threat of conquest. It lasted for twelve years and had four distinct stages.
== Significance ==
The conjoined army of Elves under Gil-galad, High King of the Ñoldor, King Oropher of the Woodland Realm and King Amdír of Lothlórien joined with Elendil's host from Arnor and Gondor to create the most significant force assembled in Middle-earth since the landing of Ar-Pharazôn. The Last Alliance was the largest military union of the Free Peoples of the world, and the only large-scale war fought until the climax of the War of the Ring an age later. After this war, the Elves of Middle-earth could never muster a force of this strength again.
=== Dwarves ===
Durin IV was the King of Durin's Folk during the War of the Last Alliance, and he sent an army of Dwarves of Khazad-dûm to fight alongside the Last Alliance of Elves and Men to help in the battles. It is said that very few Dwarves fought on either side, but the Longbeards fought alongside the Last Alliance.
== History ==
=== Prelude ===
Having been weakened in the Akallabêth it took Sauron some time to rebuild his physical form. Once he had done so he became aware that Elendil had survived the Downfall and that his sons Isildur and Anárion had founded a realm next to Mordor itself. Determined to crush the Númenórean exiles before their realms could take root, Sauron launched a surprise attack on Minas Ithil in SA 3429, taking the city and burning the White Tree of Gondor.
However he struck before his own power was fully rebuilt and in his absence the power of Gil-galad had grown stronger, even drawing nigh to Mordor itself. While Anárion defended Osgiliath, Isildur sailed north to Arnor to take counsel with Elendil. Realizing that they had sufficient power to strike back, Elendil and Gil-galad formed the Last Alliance of Elves and Men, with the aim of putting an end to Sauron for good.
Because Elendil and Gil-galad had taken the initiative, they had the luxury of time to prepare for the coming battles. Both kings spent two years gathering their forces; Elendil and Isildur met Gil-galad at the watchtower of Amon Sûl on Weathertop, and together they led their hosts to Rivendell, where they were joined by Elrond and his company of Elves. In Rivendell, they spent a further three years making plans, forging weapons, and training for the great battle ahead of them. This was the reason Rivendell was also known as "The Great Forge.
=== Conflict ===
Crossing the Misty Mountains, they journeyed south down the River Anduin, gathering Elves led by Oropher and Amdír, the kings of Greenwood and Lórien, respectively, and eventually were joined by the army of Gondor led by Isildur's brother Anárion and an army of Dwarves of Khazad-dûm.
The decisive battle took place before Mordor, on the plains of Dagorlad. It was here when the Last Alliance destroyed Sauron's main force. Although this was a victory, many were lost, including both kings Amdír and Oropher, due to their annoyance at following the supreme command of Gil-galad, the High King of the Ñoldor, and thus charging prematurely at the enemy. Many Silvan Elves were also killed alongside Oropher, and so were many Elves and Men. Oropher's army fell in the face of the Black Gate, but Amdír and his army were driven back all the way to the Dead Marshes, where they were slain bitterly. The bodies of these Elves stayed preserved in the Marshes up until Frodo and Sam passed with Gollum.
After this battle, the Black Gate was breached by the Alliance and the Siege of Barad-dûr began, lasting seven years, during which Anárion, son of Elendil and lord of Minas Anor, was killed by a rock cast from Barad-dûr. The war ended when Sauron himself came forth and fought Gil-galad in combat, who was then joined by Elendil. Although they both fell, they managed to defeat Sauron and bring him down. Isildur in the same hour then subsequently cut the One Ring from Sauron's hand, dispersing his spirit.
It should be noted that while the Last Alliance was named as of Elves and Men, Tolkien states that in fact, all living races came to battle that day, even birds and beasts and that all were found on either side except for the Elves, who fought solely under the banner of Gil-galad.
=== Aftermath ===
After this defeat of Sauron, several notable things occurred. The war brought a close to the Second Age and began the Third Age. The High Kingship of the Dúnedain passed to Isildur, son of Elendil; however, the death of Gil-galad ended the line of High Kings of the Ñoldor, and the titles of King of Lindon and High King of the Elves in Middle-earth ceased to be, because no one had the authority to claim them. Also, Thranduil and Amroth became the kings of Greenwood and Lothlórien, respectively, after the deaths of their fathers Oropher and Amdír.
Three years after the war ended, Isildur was killed at the Gladden Fields, and the One Ring was lost in the river for two and a half millennia. Sauron fled into the East, returning after a thousand years to Dol Guldur and becoming known as "the Necromancer.