Isabella Thornton (Lara Pulver) is a secondary antagonist in the third season (2009) of the TV series "Robin Hood".
Isabella is the daughter of Sir Roger of Gisborne (Paul Hilton) and the sister of Guy of Gisborne (Richard Armitage). She is introduced in the fifth episode, having recently escaped her husband, Lord Thornton (Nicholas Gleaves). Robin (Jonas Armstrong) saves her from being taken back. She begins a romantic relationship with Robin and begins to flirt with Prince John (Toby Stephens) in order to compete for his favor with her brother.
While initially helping our heroes in achieving their goals, she later betrays Robin, after he refuses to live with her and start a fresh life somewhere else. She joins Prince John's side. After Gisborne is outlawed and imprisoned, he appoints Isabella as the new Sheriff of Nottingham.
Isabella lightly cuts Robin's neck with a poisoned knife. After doing so, Robin kills Isabella and Valsey by shooting a burning arrow into the byzantine barrels, exploding them. A few hours later, the poison takes place, and Robin dies in Sherwood Forest.