Oberyn Martell

Prince Oberyn Martell, also known as the Red Viper of Dorne, is a member of House Martell, the ruling family of Dorne, the younger brother of Doran Martell and the late Elia Martell, the father of eight bastard girls known as the Sand Snakes, and a member of the Small Council for Dorne to Tommen I. He was renowned for his skill with a staff, his spirit for vengeance, and fluid sexuality.

Prince Oberyn was the younger brother of Prince Doran Martell and Princess Elia Martell, and like most members of House Martell, he was styled "Prince" instead of "Lord." He was nicknamed "the Red Viper" for his knowledge of poisons and for his unusual, deadly style of combat. Oberyn was known for being an accomplished warrior, but he was just as infamous for his sexual appetite, which extends to both men and women; Tyrion Lannister tells Bronn that Oberyn is "famous for fucking half of Westeros."

When he was a teenager, Oberyn accompanied his sister Elia on a visit to Casterly Rock. While there, Oberyn and Elia were eager to see the "monster" that had just been born. Cersei finally showed them Tyrion, but the Martell siblings were disappointed to see that he was merely a baby, and somewhat disturbed by Cersei's already strong hatred of him.

Prince Oberyn trained at the Citadel in his youth, in order to become a maester. Although he ultimately grew bored and abandoned his studies, he managed to forge several links in a maester's chain, and became well versed in the use of poisons in the process. When he was sixteen, an older nobleman caught Oberyn in bed with his mistress and wife, and challenged Oberyn to a duel to first blood. Oberyn won the duel, and several days later the man died from festering wounds, likely because Oberyn had poisoned his blade. Oberyn also traveled to Essos in his youth. For a time, he served in the mercenary company known as the Second Sons. He once went to the city of Astapor and saw the Unsullied there, whom he later remarked were impressive on the battlefield, but less so in the bedroom. He lived in Essos for a total of five years.It is implied that Oberyn fought duels in the infamous fighting pits of Meereen, as he mentions to Tyrion that he learned some of his combat techniques "during his years in the fighting pits."

Despite his wayward ways and liberal attitude towards sexuality, Oberyn was very devoted to his family. He was very close with his sister, Elia, and took her death very hard. As a result, he had a strong and fierce hatred for House Lannister, especially towards Tywin Lannister, whom he believed ordered his sister's murder. He also developed a resentment toward his deceased brother-in-law Rhaegar Targaryen for (from Oberyn's perspective) being unfaithful to Elia and "stealing away another woman", which in turn led to a war that cost all of them their lives.

Despite their very different personalities, he was also close to his older brother, Doran.