The Invasion was a professional wrestling storyline in the World Wrestling Federation (WWF, now known as WWE) that ran from March–November 2001 and involved stables of wrestlers purporting to represent World Championship Wrestling (WCW) and Extreme Championship Wrestling (ECW)—which merged to form The Alliance—placed against a stable of wrestlers purporting to represent the WWF. The storyline began shortly after the WWF's acquisitions of WCW and ECW in March and April 2001, respectively, and concluded with a "winner takes all" match between The Alliance and the WWF at Survivor Series.