Shae

Shae is a major character in the second season. She initially appeared as a recurring character in the first season and debuted in "Baelor." She is played by starring cast member Sibel Kekilli. Shae is a prostitute who has begun an exclusive relationship with Tyrion Lannister. He has arranged for her to work as a handmaid to Sansa Stark so that she can be close to him in King's Landing.

Background
Shae is a young woman who has dreams of marrying into wealth and power, despite her low social status as a camp follower. She is not from Westeros, but refuses to divulge her true origins.

Season 1
Shae is a camp-follower whom Bronn finds attached to the Lannister army in the Riverlands. He gives her to Tyrion as a present. Tyrion is charmed by her immediately. Tyrion attempts to learn more about Shae's past but she refuses to reveal specifics. She was not low-born, her mother was not a whore and her parents are together. Shae deflects Tyrion's questions and learns about his past, particularly the incident involving his marriage to Tysha. Following a victory in the Battle of the Green Fork Tyrion is made acting Hand of the King by his father Tywin Lannister. Tywin had been named as Hand to his grandson Joffrey Baratheon but planned to remain in the field. Tywin forbade Tyrion taking Shae to court. Tyrion complains about his father to Shae, then decides to defy his order, much to her delight.

Season 2

 * Main: Shae Season 2

Shae accompanies Tyrion to King's Landing and he installs her secretly in the Tower of the Hand. Varys discovers Shae's presence and subtly threatens Tyrion with the information. Shae becomes increasingly fed up at her confinement and Tyrion arranges for her to serve as a handmaid to the captive Sansa Stark. Sansa comes to trust Shae and confides her hatred of King Joffrey Baratheon after she is injured in the Riot of King's Landing. Shae warns her to trust no-one.

In the books
In the Song of Ice and Fire novels, Shae is a camp-follower who attaches herself to a Lannister army and later comes into contact with Tyrion Lannister. She is young and attractive, with an interest in power. Unlike the TV series, Shae in the books is common-born, from Westeros and not particularly subtle or mysterious.