Ser Oswell Whent was a knight of House Whent and of the Kingsguard. He served under Lord Commander Gerold Hightower in the Kingsguard of King Aerys II Targaryen until his death in 283 AC. He was remembered for his dark sense of humour.
Ser Oswell served as a loyal member of the Kingsguard, mentoring Ser Jaime Lannister. He seems to make visits to see his brother, Lord Walter Whent, from time to time, as he had only just returned from a visit when the Tourney of Harrenhal was announced, according to Ser Barristan Selmy.
Ser Oswell was present at the tourney when Jaime was named to the Kingsguard. he rides to protect the honour of his niece. At some point he is unhorsed, leaving Lyanna Stark to be crowned the Queen of Love and Beauty.
During Robert's Rebellion Oswell, along with Gerold and Ser Arthur Dayne, is notably absent from the fighting. Whilst Prince Lewyn Martell, Ser Jonothor Darry and Ser Barristan all fight at the Battle of the Trident, these three are all absent. They have been left to guard the captive Lyanna at the Tower of Joy in Dorne, it is discovered. Lord Eddard Stark rides to find his sister along with six companions, including Ethan Glover, Lord Willam Dustin and Howland Reed. Ser Oswell dies at the Tower, alongside both his Kingsguard brothers, and 5 of Ned's companions. His body is buried under a cairn at the Tower of Joy.