The Doom of Valyria was a catastrophic event that led to the fall of the once-great civilization of Valyria, known for its advanced knowledge of magic and dragon-riding. This disaster, which occurred around 400 years before the events of A Song of Ice and Fire, is believed to have been caused by a volcanic eruption or a cataclysmic event, resulting in the destruction of the Valyrian Freehold and the death of most of its inhabitants. Only a few families, such as the Targaryens, survived the Doom by fleeing to the island of Dragonstone before the disaster struck. The fall of Valyria marked the end of its dominance in the known world and led to the rise of new powers, including the Targaryens, who would later seek to reclaim their ancestral homeland.