The Invasion (professional wrestling)

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.

The idea of a supercard featuring the two top promotions of the Monday Night Wars was considered to be a dream match scenario in the eyes of many fans, as it would allow the fans to see which promotion would be superior in storyline. The angle began when Mr. McMahon's son, Shane McMahon, announced as part of the storyline on WWF's Raw Is War and the final episode of WCW's Nitro (which merged into a simulcast) that he had bought WCW from under his father's nose. This led to several run-in appearances of WCW wrestlers during Raw Is War and SmackDown! over the months after WrestleMania X-Seven.

In June 2001, the angle grew in intensity as the WWF storylines somewhat abated to make room for the central Invasion storyline. WCW and ECW merged to form The Alliance and challenged the WWF's control over the wrestling industry. An Inaugural Brawl took place at the WWF Invasion pay-per-view, where Stone Cold Steve Austin defected and joined The Alliance. Many inter-promotional matches occurred after the Invasion between The Alliance and the WWF, leading up to the climax of the angle at Survivor Series, when Team WWF (The Rock, Chris Jericho, Big Show, The Undertaker, and Kane) defeated Team Alliance (Stone Cold Steve Austin, Kurt Angle, Rob Van Dam, Booker T, and Shane McMahon) in a Winner-Take-All elimination tag team match.

...
Wikipedia