House Whent is a noble house of The Riverlands and a sworn vassal of House Tully. They rule the lands of Harrenhal. They were raised to Lords of Harrenhal by King Maekar I Targaryen after they defeated House Lothston, who had been the previous lords of Harrenhal. The head of House Whent at the start of the book was Lady Shella Whent, however she had no known heirs. They emblazon their banner with 9 bats on a yellow background.
History
The Whents are the seventh noble house to be granted Harrenhal, the six previous houses having died out over thee 300 years since Harrenhal was built. They were raised to Lords of Harrenhal after they helped Maekar defeat the mad Danelle Lothston when she raised her banners in rebellion. They had originally been knights in service to the Lothstons.
Hoster Tully married a lady of House Whent, Minisa Tully. She gave him three children, Lady Catelyn Stark, Lady Lysa Arryn and Ser Edmure Tully. From this we can assume that Minisa doesn't follow the trend of infertility in House Whent, although her daughter, Lysa, might.
The Tourney of Harrenhal was hosted by Lord Walter Whent, who named his daughter the Queen of Love and Beauty. The tourney was won by Prince Rhaegar Targaryen, although four of Lord walter's sons were beaten, as well as his brother, Ser Oswell Whent. This was also the tournament where Rhaegar met Lyanna Stark, where the story of the Knight of the Laughing Tree occurred and where Ashara Dayne was dishonoured, according to Ser Barristan Selmy.
Ser Oswell Whent was a knight of the Kingsguard for Aerys II Targaryen. He served as a mentor to Ser Jaime Lannister, and as a friend to Rhaegar. He died during Robert's Rebellion, fighting at the Tower of Joy alongsider Ser Arthur Dayne and Lord Commander Gerold Hightower. His body was buried in the red mountains of Dorne.
Books
A Game of Thrones
Catelyn thinks of Lady Whent, and notes that she is the last of her line, living with ghosts in the cavernous halls of her castle. One of the knights who help her detain Tyrion Lannister is sworn to House Whent, Ser Willis Wode.
Lady Whent yields the castle to Lord Tywin Lannister when his army approaches, as she does not have the strength in numbers to defend it. She is stripped of her titles and the castle is granted to Janos Slynt, Commander of the City Watch of King's Landing, by King Joffrey I Baratheon for the part he played in subduing Eddard Stark.