Real World:
During the week of March 26th, 2001, Vince McMahon, owner of the World Wrestling Federation, bought World Championship Wrestling.

During the week of March 26th, 2001, Vince McMahon, owner of the World Wrestling Federation, finalized a deal to buy World Championship Wrestling. His son, Shane McMahon, then stole WCW out from under his father by signing the contract first.
A few weeks after the sale, various WCW wrestlers began appearing on WWF programming and causing havoc. Eventually, some WCW matches started being aired on the WWF shows as the feud progressed.
The feud sucked, being mismanaged from the start (most notably Buff Bagwell’s totally lackluster performance during a WCW World Title match against Booker T, an effort so horrible it caused Bagwell to be fired immediately after the broadcast), and rejuvenation was needed. So, on July 9, 2001, during a match on WWF Raw, two former Extreme Championship Wrestling stars, Rob Van Dam and Tommy Dreamer, ran down to the ring to wreak havoc. WWF stars Tazz, Raven, Rhyno, the Dudley Boyz, and Justin Credible (along with ringside announcer Paul Heyman)—all former ECW stars—run out and defect to the newly formed ECW.
Later in the show, WCW and ECW announce that they’ve joined forces to become The Alliance, whose goal was to completely take over the WWF. Shane had sold his WWF stock to buy WCW, and it’s revealed that Stephanie McMahon sold hers to buy ECW. The (incomplete) initial roster of the Alliance:
Rob Van Dam, Tommy Dreamer, Tazz, Raven, Rhyno, the Dudley Boyz, Justin Credible, Booker T, Diamond Dallas Page, Billy Kidman, Hurricane Helms, Chuck Palumbo, Sean O’Hare, Mark Jindrak, Sean Stasiak, Chris Kanyon, Chavo Guerrero, Jr., Hugh Morrus, Mike Awesome, Lance Storm.
The angle was just what the WWF needed, as ratings skyrocketed immediately and kept going up for weeks after the Alliance’s inception.
It turned out to be a temporary high, though, as ratings plummeted back down when this “Invasion” wasn’t managed and written much better than the first version. Kurt Angle flopped as a babyface WWF Champion, and fans weren’t willing to buy Stone Cold Steve Austin nor Angle as a heel Alliance members once they defected to that side. It also didn’t help that little was done to legitimate the Alliance as a major threat, since WWF stars held almost all of the title belts throughout the feud—and the Alliance members who did win belts were mostly WWF stars in reality (as opposed to WCW and ECW people who hadn’t been working in the WWF prior to the start of the Invasion).
And so, at Survivor Series ‘01 on November 19th, 2001, Team WWF (The Rock, Chris Jericho, the Big Show, the Undertaker, and Kane) won a “winner take all” tag team elimination match against a team fielded by the Alliance (Stone Cold Steve Austin, Rob Van Dam, Shane McMahon, Booker T, and Kurt Angle) to completely dissolve the Alliance.
The following night on Raw, it was revealed that when Shane and Stephanie McMahon sold their WWF stock to finance the Invasion, they sold it to none other than…Ric Flair, who returned to WWF television for the first time since early 1993 to kick off the next big angle.