he fourth season of Charmed, an American supernatural drama television series, began airing on October 4, 2001 on The WB. Airing on Thursdays at 9 P.M., the season consisted of 22 episodes and concluded its airing on May 16, 2002.

This season also saw the introduction of Rose McGowan as Paige Matthews - half-sister to Prue, Piper and Phoebe - and a slight alteration of the opening sequence, due to the third season departure of Shannen Doherty as Prue.

Warner Bros. Entertainment released the complete fourth season in a six-disc boxed set on February 28, 2006.

Overview from themoviedb.org