House of the Dragon (2022) chronicles the beginning of the end of House Targaryen, detailing the events leading up to and during the devastating Targaryen civil war known as the 'Dance of the Dragons.' The series begins nearly two centuries before the events of 'Game of Thrones,' with King Jaehaerys I Targaryen's reign ending and his grandson, Viserys I, chosen as his successor over his elder female cousin, Rhaenys. King Viserys I, after losing his wife Aemma Arryn and their newborn son, defies tradition by naming his only surviving child, Princess Rhaenyra, as his heir, making her the first woman to be named heir to the Iron Throne. This decision immediately sows discord, especially with his ambitious younger brother, Daemon Targaryen, and later with his new wife, Alicent Hightower, the daughter of his Hand, Otto Hightower. Otto consistently schemes to put his grandson, Aegon II, Viserys's firstborn son with Alicent, on the throne instead of Rhaenyra.
Years pass, and the simmering tensions between Rhaenyra and Alicent, who were once childhood friends, escalate into a bitter rivalry. Rhaenyra marries Laenor Velaryon and has three sons, Jacaerys, Lucerys, and Joffrey, whose paternity is widely whispered to be Ser Harwin Strong rather than Laenor. Meanwhile, Alicent gives birth to Aegon, Helaena, and Aemond, all full-blooded Targaryens. The court becomes deeply fractured, with 'Greens' supporting Alicent's children and 'Blacks' supporting Rhaenyra. Key events include Daemon Targaryen's various exploits, including his conquest of the Stepstones and his eventual marriage to Rhaenyra after Laenor's staged death.
Viserys, increasingly ill and weakened by a slow, painful disease, struggles to maintain peace within his family and kingdom. His final moments involve a misinterpreted conversation with Alicent, where he speaks of Aegon the Conqueror's dream of 'The Prince That Was Promised,' leading Alicent to believe he wished for their son Aegon to be king. Following Viserys's death, Otto Hightower and the 'Greens' conspire to crown Aegon II, keeping the king's death a secret from Rhaenyra, who is at Dragonstone. When Rhaenyra learns of her father's death and Aegon's coronation, she is crowned queen by her supporters, igniting the civil war. Both sides begin to gather allies and dragons. The first major casualty of the war comes when Aemond Targaryen, riding Vhagar, pursues and kills Rhaenyra's son Lucerys Velaryon and his dragon Arrax over Storm's End, an act that irrevocably plunges Westeros into the brutal 'Dance of the Dragons.'
