Beyoncé used the alter ego Sasha Fierce prominently during promotion of her 2008 album I Am... Sasha Fierce.
The album was structured as two discs: I Am..., containing more introspective ballads, and Sasha Fierce, containing more assertive and performance-oriented songs. Beyoncé described Sasha Fierce as a stage persona that represented a bolder side of her public performance identity.
The album produced major singles including “If I Were a Boy,” “Single Ladies (Put a Ring on It),” and “Halo.” It was commercially successful and earned multiple Grammy Awards, including Song of the Year for “Single Ladies” at the 52nd ceremony.
Sasha Fierce was not a separate singer or a band. Beyoncé later said she had retired the persona, although the name remains strongly associated with this album era and its visual performances.