Why did House Targaryen leave Valyria?
Twelve years before Valyria was destroyed by the mysterious "Doom," Aenar Targaryen's daughter, Daenys the Dreamer, had a prophetic vision of Valyria being destroyed, so he decided to take his family to Dragonstone.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: Why did House Targaryen leave Valyria?
### Input: 
### Response: Twelve years before Valyria was destroyed by the mysterious "Doom," Aenar Targaryen's daughter, Daenys the Dreamer, had a prophetic vision of Valyria being destroyed, so he decided to take his family to Dragonstone.