The eldest of Prince Doran Martell's children, Arianne is perhaps the most notable member of the Dornish ruling house in the books, making the presumptive culling of her character a surprise. First introduced in A Feast For Crows, she sees her father as a weak ruler, never being made privy to the details of his secret continued support for House Targaryen, which included the marrying of his only daughter to Daenery's brother Viserys before his death scuppered that plan and prompted the pursuit of a Quentyn/Daenerys betrothal as a second option. As a result of this, she is first introduced as being openly rebellious to her father's rule in the wake of her uncle Oberyn's death, seducing Arys Oakheart, the Kingsguard member assigned to protect Myrcella Baratheon during her time in Dorne. With his support, she seeks to crown Myrcella as Queen of Westeros in lieu of her younger brother Tommen, in accordance with Dornish customs that place age ahead of gender in determining successors. Hoping to initiate a war with the Lannisters through this action, she is stopped and imprisoned by her father, who finally informs her of the intricacies of his master plan and seeks to involve her in it when the presence of Aegon becomes apparent, dispatching her to meet with him in one of the first publically-revealed chapters from The Winds Of Winter. As Obara, Tyne and Nymeria, three of the 'Sand Snakes' that exist as bastard daughters of Oberyn (and are noted as being close to their cousin), have been cast, it would seem that a combination of one or more of them will take Arianne's place, though such a switch does seem odd owing to their minor status in comparison to her fairly major one, though the additional removal of Aegon does render her major ongoing storyline obsolete. Without him, however, it's a mystery as to how the television series will incorporate Dorne's 'defection' from the Iron Throne into the narrative.
