Weeping War
Military action
The Weeping War was a battle that culminated on 15 Flamerule, 714 DR, in which the Akh'Velahr (the army of Cormanthor) were defeated by the invading demonic forces named the Army of Darkness, leading to the fall of the elven city of Myth Drannor, the greatest and most powerful bastion of civilization by far at the time.
https://forgottenrealms.fandom.com/wiki/Weeping_War
Origins
The exact power responsible for the original demonic summoning is unknown, but it is believed to have been a flind or orc shaman, or a human archmage. This unknown individual summoned yugoloths to raid the lands of the Dragonreach, but Aulmpiter, Gaulguth, and Malimshaer broke free of their master's control and rounded up huge numbers of goblinkin in the surrounding area.
Helmgrove
Word of this large army reached Captain Fflar of Myth Drannor, who set a watch post north of the city at Helmgrove, appointing the company named the Shield of Myth Drannor to it. The entire company was destroyed by the demonic forces.
Burnt Ridge
A second pre-battle stand was made at Burnt Ridge, where hundreds of the defending wizards were killed.
Evacuation
Fflar set about evacuating the city of all non-combatants, but this began too late and the evacuation continued even as the battle began.
Siege of Shadow
The siege of Myth Drannor by the Army of Darkness was named the Siege of Shadow and began on 21 Kythorn, 714 DR. The forward army and the best wizards have been defeated by this point, and only three thousand defenders remain.
Battle
Thousands of the Army of Darkness were slain in the battle itself, but they were far too numerous to be stopped by the defenders. They overran the city, burning and pillaging it entirely. Much destruction was caused when wizard towers, still occupied by wizards who had refused to leave, were blown apart, spreading much devastation and unpredictable magic across the city.
The Banes' Duel
At the climax of the battle, Aulmpiter called Fflar forward and the two engaged in one-on-one combat that became known as the Banes' Duel. Both Fflar and Aulmpiter were slain when a magical blast engulfed them. Their bodies were never recovered, but Fflar would be resurrected in 1374 DR by Seiveril Miritar.
Aftermath
Only two hundred elves and allies out of the 3000 who remained behind to defend the city escaped. After this, the directionless remnants of the Army of Darkness spread out as far as Sembia. The elves living in the woods around Myth Drannor spent two years ridding their land of the bugbears, flinds, gnolls, and orcs who had been part of the army, taking heavy casualties. The elves who took over the ruins of the city ensured that the surrounding area was closed off from outsiders and those of other races so that another army could not invade.
