Doom of Valyria
The Doom of Valyria is the name for the cataclysm of an unspecified nature that destroyed the Freehold of Valyria and caused the collapse of its empire. The Doom fragmented the land surrounding the city itself into numerous smaller islands, creating the Smoking Sea between them. This occurred approximately a century before the Targaryen Conquest of Westeros. The area is now described as "demon-haunted", and most people are afraid to go there, saying, "The Doom still rules in Valyria." Many of Valyria's secrets, such as the method for creating Valyrian steel, were lost in the Doom. A mosiac of colored glass depicts the event inside the mansion occupied by Illyrio Mopatis in Pentos.