A large scale siege of the city of Duirt by a horde of orcs, goblins, kobolds and hobgoblins (and a few other monsters as well).
The siege eventually led to a large scale attack as an Ecclesian crusader relief force managed to arrive before supplies ran out completely, and a combined effort of the relief force and the bravery of the cities defenders saved it from certain doom.
This historic event marked the city quite severely and Duirt is still rebuilding, with memorials erected in various places.