House of the Dragon: Season 1 – The first season begins approximately 200 years before the War of the Five Kings, and 100 years after the Targaryen Conquest united the Seven Kingdoms.
House Targaryen has reigned as the rulers of Westeros for five generations, and the number of dragons they possess has increased to more than ever before. At the end of the reign of King Jaehaerys I Targaryen, grandson of Aegon the Conqueror, a succession dispute arises between two of his grandchildren, which is resolved when the lords of Westeros assembled at the Great Council at Harrenhal select Viserys I Targaryen to be the royal heir ahead of his cousin Rhaenys.
Even though she had a superior claim, and largely due to her gender. The story begins a few years later when old King Jaehaerys passes away and King Viserys I ascends the Iron Throne.
Outwardly, the realm has enjoyed a golden age of peace and prosperity for over fifty years, and the Targaryen dynasty is at the height of its power. Yet factions are starting to form within Viserys’s court that threaten the stability of his reign.