Game of Thrones is set on the continent of Westeros, which was home to seven feuding kingdoms until they were united by the Targaryen family using dragons some three centuries ago. The dragons died out and the Targaryen Mad King was unseated in a civil war led by Lords Robert Baratheon and Eddard Stark, seventeen years before the series opens. Robert has ruled as King ever since, but when the series opens his rule is increasingly undermined by other factions. At the same time, two surviving Targaryen children, having grown to adulthood in exile on the eastern continent of Essos, are now planning to return and retake the Iron Throne, and to this end are seeking a military alliance with other factions.