House Targaryen of Harrenhal is a cadet branch of House Targaryen, 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. This branch of House Targaryen was established by Lord Maekar Targaryen in the year 331AC, following the extinction of House Strickland in the War of the Lords Scorned. Their sigil is a silver dragon on a black field, likely stemming from Maekar's Stark heritage.