According to Entertainment Weekly, the prominent role will be played by Chilean actor Pedro Pascal. Pascal has recently been seen on such TV shows as
Up to now the Martell family, which resides in the southernmost area of Westeros known as Dorne, has not been seen on-screen. Prince Oberyn is the first one to be introduced and he is very unhappy.
For those who want to experience the story as it unfolds, beware of minor spoilers below.
In the recent past of the "Game of Thrones" world, Prince Oberyn's sister, Elia, was murdered by the hulking Lannister-affiliated knight Ser Gregor Clegane, a.k.a. the Mountain. Oberyn arrives at King's Landing seeking revenge against Clegane in the fourth season.
The HBO show's fourth season is expected to cover roughly the second half of the third book in George R.R. Martin's bestselling book series, titled "A Storm of Swords."
The fourth season is expected to premiere sometime early in 2014.