Invasion was the first pay-per-view to feature the ongoing Invasion storyline, which featured wrestlers from the WWF taking on The Coalition, a combined force of wrestlers from World Championship Wrestling (WCW) and Extreme Championship Wrestling (ECW), later known as The Alliance.

From 1998 to 2000, the World Wrestling Federation (WWF, now WWE) held an event titled Fully Loaded.

The WWF had planned to hold a fourth Fully Loaded pay-per-view (PPV) in 2001, but canceled it in order to hold an event titled Invasion for The Invasion storyline between the WWF and The Alliance, consisting of former World Championship Wrestling (WCW) and Extreme Championship Wrestling (ECW) talent.

[4] At WrestleMania X-Seven on April 1, Shane defeated Vince in a Street Fight with some of the WCW talent in attendance, sitting in the upper-level seats at the Reliant Astrodome.

[5] At the 2001 King of the Ring, Booker T interfered during a Triple Threat match for the WWF Championship and tossed Steve Austin through the announcers table, nearly costing him the title.

[6] On the following night, the June 25 episode of Raw Is War, Shane declared his intention to invade the WWF, and the Invasion storyline started with Booker T performing a scissors kick to Vince.

[7] On the June 28 episode of SmackDown!, it was decided that Fully Loaded was to be changed to Invasion, and would feature matches between WWF and WCW.

[8] The ultimate goal, reportedly, was for WCW to "take over" one of the WWF's two primary programs, either Raw Is War or SmackDown!, and rebrand it as its own separate entity.

To test the waters for this, the final twenty minutes of the July 2 Raw Is War telecast was given over to WCW, which brought in its own commentators (Scott Hudson and Arn Anderson), ring announcer (Stacy Keibler), referee (Nick Patrick), ring apron, and Chyron graphics, to present a match between Booker T and Buff Bagwell for Booker's WCW Championship (which he had won on the final episode of Nitro).

[10] On the July 9 on Raw Is War, when then-face WCW owner Shane was scheduled to face Page in a street fight, the two instead attacked The Undertaker, turning Shane heel (Page had already debuted in WWF as a heel, as part of a stalker angle with Undertaker and his wife).

Later that night, Chris Jericho and Kane (from the WWF) fought Lance Storm and Mike Awesome (from WCW) in a tag team match.

It ended in a no contest when the ECW Alumni from both the WWF and WCW along with the debuting Rob Van Dam and Tommy Dreamer made their way to the ring.

This led to the Raw color-commentator Paul Heyman leaving the announcer's booth and declared that Extreme Championship Wrestling (ECW) has joined the invasion and stated that the invasion has been taken to the extreme, leading to some WWF and WCW wrestlers (including Raven, Lance Storm, Rhyno, The Dudley Boyz, and Tazz) defecting to ECW.

On the July 12 episode of SmackDown!, Vince said he needed the "old" Austin, an anti-hero tough character, to lead the WWF at Invasion.

As WWF seemed to be disadvantaged, Austin arrived, and returned to his old character, fighting off the WCW and ECW wrestlers.

The WWF wrestlers (Steve Austin, Kurt Angle, Chris Jericho, Kane, The Undertaker) then cleared out the ring, and were left standing tall.

[13] On the July 19 episode of SmackDown!, Heyman says that he wants to bring back wrestling, and destroy sports entertainment by giving the WWF its last rites with The Alliance members, "In nomine Patris et Filii et Spiritus Sancti, Amen!

[14] Before the event officially began, Chavo Guerrero (WCW) defeated Scotty 2 Hotty (WWF) in a match taped for Sunday Night Heat.

[16] The first match of the event was between Lance Storm and Mike Awesome (ECW), and Edge and Christian (WWF).

[17][18] The third match was between the APA (Faarooq and Bradshaw) (WWF), and Sean O'Haire and Chuck Palumbo (WCW).

X-Pac fought back after sending Kidman over the top rope, and performed a springboard reverse crossbody to the outside.

Back in the ring, Raven tossed Regal over top rope, and performed a baseball slide, and a Russian legsweep into the security wall.

[17][18] The sixth match was between The Big Show, Billy Gunn and Albert (WWF), and Chris Kanyon, Shawn Stasiak and Hugh Morrus (WCW).

After Albert tagged in, Kanyon and Morrus entered the ring, but Gunn and The Big Show threw them out.

He then shoved the referee out of the way, allowing Tajiri to spit green mist into Tazz's face, and pin him after a Buzzsaw Kick.

After Hardy missed a crossbody, Van Dam performed a standing moonsault, a lifting double underhook facebuster, and a rolling thunder.

Back in the ring, Van Dam performed a Chair Surf, and attempted a split-legged moonsault, but Hardy blocked it with his knees.

Van Dam placed the Hardcore Championship belt on Hardy, and performed a Five Star Frog Splash onto the title.

After sending the referee back in the ring, Austin turned on Team WWF by performing a Stone Cold Stunner to Angle.

[21] As the Invasion storyline concluded at Survivor Series in November,[22] this was the only Invasion PPV held, and instead of reinstating Fully Loaded in July 2002, the WWF, which was renamed to World Wrestling Entertainment (WWE) in May 2002, moved Vengeance to the July slot;[23] Vengeance had temporarily replaced Armageddon in December 2001 due to the September 11 attacks.