Game Of Thrones: 10 Storylines From The Books The Show Ignored
8. Dorne Crowns Myrcella
In the wake of Prince Oberyn's death at the hands of the Mountain, after Clegane already murdered Elia Martell and her children, all of Dorne want vengeance against King's Landing. Everyone but the one man who matters - Prince Doran. Three of Oberyn's daughters (the Sand Snakes) and Prince Doran's own daughter Arianne try to convince him to raise his spears, but he flatly refuses.
To stop the Sand Snakes from doing anything that may start a war with the Lannisters, the Prince of Dorne locks all nine of them up. However his daughter has other plans. In Dornish law, the crown passes down to the next oldest sibling regardless of gender, so in Arianne's eyes Myrcella is the rightful Queen of Westeros.
Her plan to crown the princess goes awry shortly after it starts, and is discovered and stopped almost immediately. This results in a skirmish that sees Ser Arys Oakheart, the knight of the Kingsguard sent to Dorne with Myrcella, slain by Areo Hotah.
One of Arianne's accomplices, Darkstar, would rather see the princess dead than crowned. If the Lannisters think that Prince Doran murdered Myrcella, they will be the ones to call their banners, provoking the war the Dornish want. However, Darkstar only manages to chop the princess' ear off.
Arianne Martell is furious with her father, but is soon appeased when he reveals the long game he has been playing for years...