In both the book and the show, young Princess Rhaenyra is proclaimed “the Realm’s Delight.” In “Fire & Blood,” we first hear about her at the age of six, when she’s described as “precocious,” “bright,” “beautiful,” and “bold.” She starts serving as her father’s cupbearer around the age of eight, and she enjoys a close (perhaps too close) relationship with her uncle Daemon, who assures her that she’s the “fairest maid in all the Seven Kingdoms.” She wears her silver-gold hair in braids, prefers expensive fabrics like lace and velvet in shades of red, purple, and black, and wears a lot of jewelry. Pearls, diamonds, and rings are some of her favorites. Book Rhaenyra was shapely before motherhood, but never lost the weight she’d put on during pregnancy after childbirth. Martin calls her “stout” and “thick of waist,” and says her “beauty faded by age 20.”
After a brief prologue, “House of the Dragon” opens with a shot of a teenage Rhaenyra riding her dragon, Syrax, through the skies above King’s Landing. The Princess of Dragonstone is an accomplished dragonrider in the books as well. It appears that production designers are using costumes — particularly colors — to convey meaning as the maturity, intentions, and allegiances of the characters. Perhaps that’s why young Rhaenyra (as played by Millie Alcock) often wears pastels and uncomplicated hairstyles now. After a time jump, she’s played by Emma D’Arcy, who is decked out in reds and blacks and layers of jewels, with her hair in sophisticated plaits. “House of the Dragon’s” derision about Rhaenyra’s size aside, D’Arcy looks physically and mentally sharp as adult Rhaenyra.