Which Kingsguard knight guarding Myrcella in Dorne was omitted from Game of Thrones?

Arys Oakheart is the Kingsguard knight guarding Myrcella in Dorne who was omitted from Game of Thrones.

Ser Arys is a member of the Kingsguard during the early novels and accompanies Princess Myrcella when she is sent to Dorne. His assignment places him at the Water Gardens, where he becomes involved with Arianne Martell, Doran Martell’s daughter and the heir to Dorne under Dornish succession customs.

Arianne persuades Arys to support a scheme to crown Myrcella as queen. The plan is not simply romantic rebellion: it exploits the political conflict between Dornish inheritance traditions and the succession favored elsewhere in Westeros. When the plot is discovered, Arys chooses a desperate fight rather than surrender and is killed by Areo Hotah.

The show keeps Myrcella’s journey to Dorne but replaces the novel’s Arianne-and-Arys political storyline with a different plot involving the Sand Snakes. Arys should not be confused with Meryn Trant, Boros Blount, or Preston Greenfield, all Kingsguard knights connected to the royal court but not the omitted Dorne character described here.