The Coup in Dorne is an event that takes place during the course of the War of the Five Kings, in which Prince Doran Martell and his heir, Trystane Martell, are betrayed and murdered by Ellaria Sand and the Sand Snakes in order for them to seize power in Dorne so that they may avenge Doran's younger brother, Oberyn Martell, leading to the extinction of House Martell and setting the stage for Dorne entering the conflict against House Lannister.