Game of Thrones: House of the Dragon

With both sons dead, old King Jaehaerys I Targaryen convenes a Great Council to choose an heir. The Westerosi lords select Jaehaerys' eldest grandson, Prince Viserys, over his eldest grandchild, Princess Rhaenys. Nine years into his reign, King Viserys organizes a tournament to celebrate Queen Aemma Arryn's pregnancy, confident she is carrying his long-awaited male heir. The Small Council disregards Master of Ships Lord Corlys Velaryon's warning that the Triarchy, an alliance of Essos' Free Cities, threatens to cripple Westerosi shipping lanes. The Hand of the King, Ser Otto Hightower, criticizes Viserys's brother and heir, Prince Daemon, for his brutality as the City Watch commander. At the tournament, Ser Criston Cole, a common-born knight, outcompetes Daemon, while Aemma dies in childbirth. Her newborn son, Baelon, dies shortly after. Viserys refuses the council's pleas to appoint a new heir until Ser Otto reveals that Daemon mockingly styled Baelon as, "The Heir for a Day." Outraged, Viserys banishes Daemon from King's Landing and appoints his only living child, Princess Rhaenyra, heir to the Iron Throne.

Six months after Rhaenyra is named the heir, Daemon has illegally occupied Dragonstone, supported by loyal City Watch guards. When Prince-Admiral Craghas Drahar, known as the Crabfeeder, menaces the Stepstones archipelago at the Essos Triarchy's behest, Rhaenyra suggests showing force. The Small Council dismisses this and instead relegates Rhaenyra to appointing a new Kingsguard knight. Ignoring others' advice, she chooses Ser Criston, the only knight with actual battle experience. Ser Otto sends his teen-aged daughter, Lady Alicent, to privately console the grieving king; she advises that Viserys and Rhaenyra should discuss his kingly duty to remarry. Lord Corlys and his wife, Princess Rhaenys, propose that Viserys unite their Valyrian houses by marrying their twelve-year-old daughter, Laena. Meanwhile, the Small Council learns that Daemon, proclaiming himself the true heir, stole a dragon egg and intends to marry his mistress, Mysaria, as a secondary spouse. Ser Otto and a small detachment sail to Dragonstone to retrieve the egg. Rhaenyra follows on her dragon, Syrax, and forces Daemon to renounce his false claims and return the egg to her. Viserys weds Lady Alicent, angering Lord Corlys, who then seeks out Daemon to propose an alliance.

For three years, the Stepstones conflict has escalated. Lord Corlys and Prince Daemon battle Craghas Drahar and his pirates without the Iron Throne's support. Meanwhile, King Viserys plans a great hunt to celebrate his and pregnant Queen Alicent's son Aegon's second birthday. Rhaenyra resents her father's excessive attention towards her half-brother, Aegon. The ailing king insists that Rhaenyra, now seventeen, must marry to form a strong alliance and protect their lineage. Among the suitors is Lord Jason Lannister of Casterly Rock, a match Rhaenyra opposes. Even two-year-old Prince Aegon is proposed. Lord Lyonel Strong recommends Ser Laenor Velaryon, Lord Corlys' son, to mend the rift between the two houses. Overcoming his previous doubts, Viserys assures Rhaenyra she will remain his heir and can choose her consort. Meanwhile, brothers Hobert and Otto Hightower secretly scheme to make Prince Aegon the successor, furthering their family's power and prestige. After Ser Vaemond Velaryon pleads for the king's help, Viserys agrees to send aid to the Stepstones. Seeing his brother's support as ending his chance to prove himself, Daemon acts as bait to ambush the Triarchy warriors, killing the Crabfeeder and winning the ensuing battle before the crown's forces arrive.