House Durwell

House Durwell is an extinct vassal house from the Reach of Westeros, holding allegiance to House Tyrell of Highgarden. They are mentioned in Game of Thrones: A Telltale Games Series.

Background
House Durwell was a Reach house that went extinct 200 years before the series began.

Game of Thrones: A Telltale Games Series
Sera Flowers, a handmaiden to Margaery Tyrell, adopted the alias Sera Durwell with the help of the Tyrells prior to the beginning of the game.

"Sons of Winter"
Lord Garibald Tarwick questions Mira Forrester on Sera's last name, knowing the Durwells went extinct 200 years ago. Mira can either lie to Lord Tarwick, saying she's met them, they still exist but are small, or reveal that Sera is actually a bastard.

In the books
The Durwells are mentioned in The Sworn Sword as a Reach house whose lands border House Webber, and during the reign of Aerys I Targaryen, the Durwells were renowned livestock thieves. They are however not mentioned to be extinct.