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 Invasion was a wrestling storyline in the World Wrestling Federation ( WWF ) that began after the WWF bought World Championship Wrestling ( WCW ) .