At the dawn of the first century of Targaryen rule over Westeros, the ailing King Jaehaerys Targaryean (Michael Carter) has lost both his sons. Fearing a civil war if an heir is not named, he summoned a thousand lords of the Seven Kingdoms to a Great Council to determine his succession. Only two major claims were considered: Princess Rhaenys Targaryen (Eve Best) and Prince Viserys Targaryen (Paddy Considine) (respectively his oldest grandchild, and his oldest grandson). (Wikipedia)