The Doom of Valyria

On a day one hundred and fourteen years before Aegon's Conquest, every hill for five hundred miles split asunder. The Fourteen Flames erupted as one, and ash and fire and molten rock rained upon the greatest city in the world; dragons burned in the sky, the earth drank palaces and temples whole, and the sea rushed boiling into the wound, shattering the peninsula into the island-strewn horror men now call the Smoking Sea. In a single day the Freehold of Valyria, its dragonlords, its sorceries, and near all its dragons passed out of the world, and with them the arts of spell-forged steel and much else that cannot be made again. What caused the Doom no man can say (the wrath of the gods, the failing of the fire-mages who chained the volcanoes, or some darker bargain come due), and to this day sailors swear the Doom rules Valyria still, and that no man who looks upon that coast returns.