Dragonstone is the ancestral seat of House Targaryen. It was the westernmost outpost of the Valyrian Empire. Prior to Robert's Rebellion, the island served as the seat of the heir apparent, known as the "Prince of Dragonstone". The two titles were often, though not always, synonymous. The first Prince of Dragonstone was Aenys I Targaryen, son of Aegon I . The last Prince of Dragonstone was Rhaegar Targaryen