The Fall of Myth Drannor (1998)

From the back cover:

The Fall of Myth Drannor is an accessory detailing those horrible years encompassing the Weeping War, for use with the Cormanthyr: Empire of the Elves book. Herein you will find the causes of the Fall of that most lyrical of elf cities; highlights of the twelve campaigns and their most significant battles; copious adventure hooks for involving player characters in behind-the-scenes activites; and new (or should we say ancient?) magical items and spells, most of which have been lost in time.

From the passing of Coronal Eltargrim to the shattering of the Khov Anilessa's invisible prison to the stand at Honorsgate, the painful history of the Fall lies within these pages. Now comes the opportunity for heroes to be made - or become part of the history in their attempts.