Tyene Sand

Tyene was born around the year 277, the bastard daughter of Prince Oberyn Martell and a septa, and spent part of her childhood at the Water Gardens of Sunspear. As a baby still in her cradle, her mother used to read her The Seven-Pointed Star.

She grew up close to her cousin Arianne Martell: together they learned to read, dance and ride, and shared meals, jewels, and even a flask of wine Arianne once stole. With Arianne and two of her sisters she once crossed the Mander to visit her mother.

On another occasion Tyene and Arianne fled Sunspear so that Arianne could marry Willas Tyrell at Highgarden, but Oberyn Martell caught up with them at Vaith and brought them back. It was also her father who taught her, at Ghaston Grey, how to milk venom from vipers.

At Sunspear, Tyene waits for Prince Doran Martell in the throne room to demand vengeance for her father's death, while she embroiders an image of a smiling Oberyn in red armor astride a sand steed.

When her sister Nymeria Sand proposes killing Tywin Lannister, the regent queen Cersei, Ser Jaime Lannister and King Tommen, Tyene favors another path: crowning Princess Myrcella Baratheon queen and marrying her to Trystane Martell, Doran's youngest son. If the Lannisters and Tyrells respond by invading Dorne, she proposes letting them die in the passes and sands of the country. Doran promises to consider it, and Tyene asks for his blessing; Maester Caleotte, wary of her reputation with poisons, checks her afterward for scratches and needle marks.

As a gesture of goodwill toward Tommen's court, Doran has his captain Areo Hotah confine Tyene and her sisters Nymeria and Obara in the Spear Tower, ahead of their male cousins. Soon after, Princess Arianne is also moved there, following the failure of her own plot to crown Myrcella.

Freed before Ser Balon Swann's arrival, Tyene and her sisters are told of Doran's plans and attend the banquet Dorne holds for the knight when he brings Ser Gregor Clegane's head; when Ricasso toasts King Tommen, Tyene refuses to join the toast.

After the banquet, Doran and Arianne reveal the rest of their plans to Tyene and her sisters, including blaming Darkstar for Ser Arys's death; Tyene finds the idea amusing. Doran then sends her to King's Landing, disguised as a septa, to win over the new High Septon. Now knowing what her uncle is really like, Tyene swears on her father's memory to follow him faithfully.