The "Red Viper" was not always called by such a name. He was born into the Royal family of Dorne; hence he was named Oberyn Martell, the Prince of Dorne. In his youth he was fostered by House Qorgyle at Sandstone. During his adolescence however he had been Challenged to a duel by Edgar Yronwood. A hulking man with a fierce reputation and a short temper. This duel was an ill fated event as both warriors lost more than they could have gained. Edgar Yronwood had challenged Oberyn after finding the Viper in bed with Edgar's paramour.
Due to the high birth and rank of Oberyn and being only at an age of six and ten; the duel was reduced to a first blood contest. Both warriors fought vigorously, giving and receiving cuts and a number of wounds to one another. However it was not too soon that Oberyn had recovered from his wounds while Edgar's wounds lead to his death. The wounds inflicted by Oberyn were not fatal however rumors had spread that the weapon of choice Oberyn had used was poisoned which lead to Edgar's wounds festering and his eventual demise. These rumors had made Oberyn infamous; eventually Oberyn was given the nickname the "Red Viper" by friends and foes alike.
Even to this day, it all felt like another lifetime ago. It was not soon after that he was sent to Oldtown where he had studied poisons and even achieved a high enough knowledge of the art of potions and poisons to form his first maesters chain of lead. It was not too long ago that he could recall the long days and endless nights of reading and scouring over scrolls and manuals in Oldtown. He could even recall the experiments and test he had conducted on carious patients and victims.
However those days are over and done with. This please barge is days away from reaching it's destination of Lys. Oberyn felt it best to leave Westeros and carve out a life of his own in a strange new world. People had called his departure an exile however he never view it as such and always planned to return back to his homeland of Donre.