|Died||In 130 AC, at King's Landing|
The World of Ice & Fire (mentioned)|
Fire & Blood (mentioned)
During the storming of the Dragonpit, Ser Willam was one of the Seven Who Rode, who were sent by Rhaenyra Targaryen to recover her son, Prince Joffrey Velaryon, as he tried to save the dragons from the Dragonpit. Prince Joffrey was killed after falling off the dragon Syrax, with a mob tearing off his remains. While trying to recover his body, Ser Willam was one of the three of the seven who were killed, with a man leaping down upon him from a rooftop to land on his back, with the Valyrian steel sword Lamentation he bore being torn from his hand, never to be found again.