The following contains potential spoilers for HBO's House of the Dragon.
George R.R. Martin's Fire & Blood depicts the violent and cruel rivalry between Princess Rhaenyra Targaryen and Queen Regent Alicent Hightower as they fight over the Iron Throne. In adapting the novel for the HBO spinoff series House of the Dragon, a few notable changes have been made to create a nuanced layer to their relationship.
Like its source material, House of the Dragon is set approximately 200 years before the events of Game of Thrones. It'll trace the Targaryens' rule of the Seven Kingdoms at their highest and lowest points, the latter of which is the civil war known as Dance of the Dragons. House of the Dragon will explore the complications of being women in the power in the world of Westeros... or at least women who wish to be in power. By far the most important dynamic is between the intimidating Rhaenyra Targaryen and Alicent Hightower, whose relationship starts off on a much lighter note.
In Fire & Blood, Rhaenyra was named heir to the Iron Throne at age eight and was expected to be the first ruling Queen of Westeros. However, this plan fell apart after her father Viserys married Alicent Hightower -- a woman nine years older than Rhaenyra. When Alicent gave birth to a boy, it was assumed he would be named heir before Rhaenyra. That didn't happen and the Kingdom was split between supporting the "Greens" (the Queen Regent) and the "Blacks" (the Princess). Rhaenyra and Alicent got along when they became stepdaughter and stepmother, but never had a tight bond, making it much easier for Alicent to conspire against her stepdaughter.
House of the Dragon is looking to make this relationship a much bigger tragedy. The first major change to both characters is their age. The showrunners seem to have aged up Rhaenyra to be closer to Alicent's age and made them childhood friends. Narratively, it makes much more sense to make them best friends at first. When the ultimate division between the Greens and Blacks in the Kingdom does occur, it'll be much more impactful and dramatic. Best friends finding themselves at war over power -- especially knowing Alicent tries to kill Rhaenyra with a certain special blade -- is Shakespearean tragedy at its best.
The characters' relationship will also be much more complicated and empathetic. The age difference between Rhaenyra and Alicent in the book didn't allow them to connect in a meaningful way, even if they did enjoy each other's company. The show, on the other hand, opens many doors for small acts of betrayal to slowly break down their bond. Just having Alicent marry Viserys puts an awkward strain on their relationship because Rhaenyra's best friend becomes her stepmother. Imagine the discussions they have at the dinner table after that.
By dramatically changing their relationship, House of the Dragon is avoiding the "evil stepmother" trope and relying on a thorny tale of best friends turned enemies. It's a powerful tool in both the storytelling sense and in the strategy that comes with war. Like most childhood friends do, Rhaenyra and Alicent may have entrusted each other with their deepest secrets. And if there's one thing Game of Thrones taught viewers, it's that a secret is the greatest weapon there is.
House of the Dragon debuts on HBO and HBO Max on Aug. 21.