House Targaryen is a noble family of Valyrian descent that escaped the Doom. They lived for centuries on the island of Dragonstone until Aegon the Conqueror and his sisters rode their dragons in their conquest of the Seven Kingdoms.
House Targaryen ruled as the kings on the Iron Throne and as the Great House of the crownlands for nearly 300 years, until their ouster in Robert’s Rebellion, which they call the War of the Usurper. Their seats were the Red Keep in the capital city of King’s Landing, the castle of Dragonstone, and the summer residence of Summerhall.
House Targaryen’s sigil is a three-headed dragon breathing flames, red on black. The three-headed dragon represents the Conqueror and his two sisters, Rhaenys and Visenya. Their house words are “Fire and Blood.” Some Targaryen armor was black steel with helms crested with dragon scales.
Although the Targaryen kings took their seat at King’s Landing, the place where Aegon and his army first landed in Westeros and made their first fort, Dragonstone remained the traditional seat of the heir-apparent to the throne, who was known as the Prince of Dragonstone. Younger siblings of the heir could receive Summerhall and be known as the Prince of Summerhall.