Unlike the other major families of Game of Thrones, the Targaryens aren't native to Westeros, and actually came to the continent hundreds of years ago from the city of Valyria. Their sigil, a three-headed dragon, is appropriate, as their command of the flying, fire-breathing beasts was what allowed them to completely conquer and unite the continent. After almost three hundred years of rule, however, the dragons have gone extinct and the house descended into decadence and madness, which led to Robert Baratheon's rebellion.

At the start of Game of Thrones, the only remaining members of the Targaryen family are Viserys and his sister Daenerys, as the rest of their family was put to death during the rebellion. In an attempt to marshal forces strong enough to retake his family's throne, Viserys marries his sister to Khal Drogo of the Dothraki on the continent of Essos. Viserys' cruelty and entitlement eventually becomes his undoing, however, as Khal Drogo puts him to death for his insolence, making Daenerys the sole remaining Targaryen.