From A Wiki of Ice and Fire
|Title|| Lord of Yronwood|
Warden of the Stoneway
|Died||In 274AL, at Yronwood|
|Book(s)|| A Storm of Swords (Mentioned)|
The Winds of Winter (Mentioned)
When Oberyn Martell was sixteen, he was found abed with Lord Edgar's paramour. A duel between the two ensued, though only to first blood in due to Oberyn's youth and high birth. Both men took cuts. However, while Prince Oberyn soon recovered, Lord Edgar's wounds festered and he died. Afterward it was rumored that Oberyn had poisoned his sword, gaining his nickame of "The Red Viper".