One of the ancient houses of the Freehold of Valyria, the Targaryens were one of the few families to survive the Detom of their home. They escaped to sail from the disaster, leading a remnant of their dragon-ruling people to the westernmost outpost of Valyrian influence, Dragonstone. A couple hundred years later, under Aegon the Conqueror and his sisters, the Valyrians and lords of Dragonstone were invading the realms of Westeros. Although the Targaryen kings took their seat at King’s Landing, the place where Aegon and his army first landed and made their first fort, Dragonstone remained the traditional seat of the heir-apparent to the throne. Their motto is, “Fire and Blood.”
King Aerys II Targaryen was the last ruling king of his line after nearly 300 years of unbroken rule. Lord Robert Baratheon ascended to the Iron Throne in the year 283 after successfully leading a rebellion against the Targaryens which erupted after Aerys’ unjust murders of several important lords and other atrocities.
Aerys’s only remaining children after the death of his heir and eldest son Rhaegar, Viserys and the new-born Daenerys, were taken away by Ser Willum Darry from Dragonstone to Braavos to seek aid from the merchant princes of the Free Cities and then to eventually beg their way through life until only recently.
The three-headed dragon represents Aegon the Conqueror and his two sisters, Rhaenys and Visenya, as well as their three dragons: Vhagar, Meraxes, and the dreaded Balerion.
Information about House Targaryen that reveals spoilers from the books.