World Wrestling Federation/Entertainment (1999–2005)
In the weeks before Jericho's debut, a clock labeled "countdown to the new millennium" appeared on WWF programming. On the home video, Break Down the Walls, Jericho states he was inspired to do this as his entrance when he saw a similar clock in a post office and Vince McMahon approved its use as his introduction to the WWF. The clock finally ran out on the August 9 episode of Raw Is War in Chicago, Illinois while The Rock was in the ring cutting a promo on the Big Show. Jericho entered the arena and proclaimed "Raw Is Jericho" and that he had "come to save the World Wrestling Federation", referring to himself as "Y2J" (a play on the Y2K bug). The Rock proceeded to verbally mock Jericho for his interruption. Later that month, Jericho would interact with several superstars including in particular interrupting a promo that The Undertaker was involved in. Jericho made his in-ring debut as a heel on August 26, losing a match against Road Dogg by disqualification on the inaugural episode of SmackDown! after he performed a powerbomb on Road Dogg through a table.
Jericho's first long-term feud was with Chyna, for the WWF Intercontinental Championship. After losing to Chyna at Survivor Series on November 14, Jericho defeated her to win his first WWF Intercontinental Championship at Armageddon on December 12. This feud included a controversial decision during a rematch in which two separate referees declared each one of them the winner of a match for the title. As a result, Jericho and Chyna became co-champions, during which Jericho turned face. Jericho attained sole champion status at the Royal Rumble on January 23, 2000, by defeating Chyna and Hardcore Holly in a Triple Threat match.
Jericho lost the WWF Intercontinental title to then-European Champion Kurt Angle at No Way Out on February 27. Jericho competed in a Triple Threat match against Chris Benoit and Angle at WrestleMania 2000 on April 2 in a two-falls contest with both of Angle's titles at stake. Jericho won the European Championship by pinning Benoit, after Benoit pinned Jericho to win the WWF Intercontinental Championship. This was the first of six pay-per-view matches between the pair within twelve months. Jericho was originally supposed to be in the main event of WrestleMania, but was taken out after Mick Foley, who was originally asked by writers to be in the match, took his place. Jericho was even advertised on the event's posters promoting the match. Jericho lost the European Championship the next night to Eddie Guerrero on Raw is War after Chyna sided with Guerrero.
On the April 17 episode of Raw is War, Jericho upset Triple H in a WWF Championship match. Referee Earl Hebner made a fast count when Jericho pinned Triple H, causing Jericho to win the title. Hebner later reversed the decision due to pressure from Triple H, and WWE does not recognize Jericho's reign as champion. On April 19, Jericho defeated Eddie Guerrero at the Gary Albright Memorial Show organized by World Xtreme Wrestling (WXW). On the May 4 episode of SmackDown!, Jericho defeated Benoit to win his third WWF Intercontinental Championship but lost the title back to Benoit four days later on Raw is War. Jericho's feud with Triple H ended at Fully Loaded on July 23, when they competed in a Last Man Standing match. Jericho lost the match to Triple H only by one second, despite the repeated assistance Triple H's wife, Stephanie, provided him in the match.
At the Royal Rumble on January 21, 2001, Jericho defeated Chris Benoit in a ladder match to win the WWF Intercontinental Championship for the fourth time. At WrestleMania X-Seven on April 1, Jericho successfully defended his title in a match against William Regal, only to lose it four days later to Triple H. At Judgment Day on May 20, Jericho and Benoit won a tag team turmoil match and earned a shot at Stone Cold Steve Austin and Triple H for their WWF Tag Team Championship on Raw the next night. Benoit and Jericho won the match, in which Triple H legitimately tore his quadriceps, spending the rest of the year injured. Benoit and Jericho each became a WWF Tag Team Champion for the first time. Jericho and Benoit defended their titles in the first fatal four-way Tables, Ladders and Chairs match on the May 24 episode of SmackDown!, where Benoit sustained a year-long injury after missing a diving headbutt through a table. Despite Benoit being carried out on a stretcher, he returned to the match to climb the ladder and retain the championship. Jericho and Benoit lost the titles one month later to The Dudley Boyz on the June 21 episode of SmackDown!. At King of the Ring on June 24, both Benoit and Jericho competed in a triple threat match for Austin's WWF Championship, in which Booker T interfered as the catalyst for The Invasion angle. Despite Booker T's interference, Austin retained the title.
In the following months, Jericho became a major force in The Invasion storyline in which WCW and ECW joined forces to overtake the WWF. Jericho remained on the side of the WWF despite previously competing in WCW and ECW. However, Jericho began showing jealousy toward fellow WWF member The Rock. They faced each other in a match at No Mercy on October 21 for the WCW Championship after Jericho defeated Rob Van Dam in a number one contenders match on the October 11 episode of SmackDown!. Jericho won the WCW Championship at No Mercy when he pinned The Rock after debuting a new finisher, the Breakdown, onto a steel chair, winning his first world title in the process. One night later, the two put their differences aside and won the WWF Tag Team Championship from the Dudley Boyz.
After they lost the titles to Test and Booker T on the November 1 episode of SmackDown!, they continued their feud. On the November 5 episode of Raw, The Rock defeated Jericho to regain the WCW Championship. Following the match, Jericho attacked The Rock with a steel chair. At Survivor Series on November 18, Jericho turned heel by almost costing Team WWF the victory after he was eliminated in their Winner Take All matchup by once again attacking The Rock. Despite this, Team WWF won the match. At Vengeance on December 9, Jericho defeated both The Rock for the World Championship (formerly the WCW Championship) and Stone Cold Steve Austin for his first WWF Championship on the same night to become the first wrestler to hold both championships at the same time, which made him the first-ever Undisputed WWF Champion, as well as the fourth Grand Slam winner under the original format. He retained the title at the Royal Rumble on January 20, 2002, against The Rock and at No Way Out on February 17 against Austin. Jericho later lost the title to Royal Rumble winner Triple H in the main event of WrestleMania X8 on March 17. Jericho was later drafted to the SmackDown! brand in the inaugural WWF draft lottery. He would then appear at Backlash on April 21, interfering in Triple H's Undisputed WWF Championship match against Hollywood Hulk Hogan. He was quickly dumped out the ring, but Triple H would go on to lose the match. This would lead to a Hell in a Cell match at Judgment Day on May 19, where Triple H would emerge victorious. Jericho would then compete in the 2002 King of the Ring tournament, defeating Edge and The Big Valbowski to advance to the semi-finals, where he was defeated by Rob Van Dam at King of the Ring on June 23. In July, he began a feud with the debuting John Cena, losing to him at Vengeance on July 21.
After his feud with Cena ended, Jericho moved to the Raw brand on the July 29 episode of Raw, unwilling to work for SmackDown! General Manager Stephanie McMahon. Upon his arrival to the brand, he initiated a feud with Ric Flair, leading to a match at SummerSlam on August 25, which Jericho lost. On the September 16 episode of Raw, he won the WWE Intercontinental Championship for the fifth time from Rob Van Dam, before losing the title to Kane two weeks later on Raw. He then later formed a tag team with Christian, with whom he won the World Tag Team Championship by defeating Kane and The Hurricane on the October 14 episode of Raw. Christian and Jericho lost the titles to Booker T and Goldust in a fatal four-way elimination match, involving the teams of The Dudley Boyz, and William Regal and Lance Storm at Armageddon on December 15.
On the January 13, 2003, episode of Raw, Jericho won an over-the-top-rope challenge against Kane, Rob Van Dam, and Batista to select his entry number for the Royal Rumble match on January 19. He chose number two in order to start the match with Shawn Michaels, who had challenged him to prove Jericho's claims that he was better than Michaels. After Michaels's entrance, Jericho entered as the second participant. Christian, in Jericho's attire, appeared while the real Jericho attacked Shawn from behind. He eliminated Michaels shortly afterward, but Michaels got his revenge later in the match by causing Test to eliminate Jericho. Jericho spent the most time of any other wrestler in that same Royal Rumble. Jericho simultaneously feuded with Test, Michaels, and Jeff Hardy, defeating Hardy at No Way Out on February 23. Jericho and Michaels fought again at WrestleMania XIX on March 30, which Michaels won. Jericho, however, attacked Michaels with a low blow after the match following an embrace.
After this match, Jericho entered a rivalry with Goldberg, which was fueled by Goldberg's refusal to fight Jericho in WCW. During Jericho's first episode of the Highlight Reel, an interview segment, where Goldberg was the guest, he complained that no one wanted Goldberg in WWE and continued to insult him in the following weeks. On the May 12 episode of Raw, a mystery assailant attempted to run over Goldberg with a limousine. A week later, Co-Raw General Manager, Stone Cold Steve Austin, interrogated several Raw superstars to find out who was driving the car. One of the interrogates was Lance Storm, who admitted that he was the assailant. Austin forced Storm into a match with Goldberg, who defeated Storm. After the match, Goldberg forced Storm to admit that Jericho was the superstar who conspired Storm into running him over. On the May 26 episode of Raw, Goldberg was once again a guest on the Highlight Reel. Jericho expressed jealousy towards Goldberg's success in WCW and felt that since joining WWE, he had achieved everything he had ever wanted in his career and all that was left was to defeat Goldberg and challenged him to a match. At Bad Blood on June 15, Goldberg settled the score with Jericho and defeated him.
On the October 27 episode of Raw, Jericho won his sixth WWE Intercontinental Championship when he defeated Rob Van Dam. He lost the title back to Van Dam immediately after in a steel cage match. Later in 2003, Jericho started a romance with Trish Stratus while his tag team partner Christian began one with Lita. This, however, turned out to be a bet over who could sleep with their respective paramour first, with a Canadian dollar at stake. Stratus overheard this and ended her relationship with Jericho, who seemingly felt bad for using Stratus. After he saved her from an attack by Kane, Stratus agreed that the two of them could just be "friends", thus turning Jericho face for the first time since 2001. After Christian put Stratus in the Walls of Jericho while competing against her in a match, Jericho sought revenge on Christian, which led to a match at WrestleMania XX on March 14, 2004. Christian defeated Jericho after Stratus ran down and "inadvertently" struck Jericho (thinking it was Christian) and Christian got the roll-up. After the match, Stratus turned on Jericho and revealed that she and Christian were a couple. This revelation led to a handicap match at Backlash on April 18 that Jericho won. Jericho won his record-breaking seventh WWE Intercontinental Championship at Unforgiven on September 12 in a ladder match against Christian, breaking the previous record held by Jeff Jarrett from 1999. Jericho's seventh reign was short lived, as he lost it at Taboo Tuesday on October 19 to Shelton Benjamin.
Jericho teamed up with Randy Orton, Chris Benoit, and Maven to take on Triple H, Batista, Edge, and Gene Snitsky at Survivor Series on November 14. The match stipulated that each member of the winning team would be the general manager of Raw over the next four weeks. Jericho's team won, and took turns as general manager. During Jericho's turn as general manager, the World Heavyweight Championship was vacated because a Triple Threat match for the title between Triple H, Benoit and Edge a week earlier ended in a draw. At New Year's Revolution on January 9, 2005, Jericho competed in the Elimination Chamber against Triple H, Chris Benoit, Batista, Randy Orton, and Edge for the vacant World Heavyweight Championship. Jericho began the match with Benoit and eliminated Edge, but was eliminated by Batista. Triple H went on to win. At WrestleMania 21 on April 3, Jericho participated in the first ever Money in the Bank ladder match. Jericho suggested the match concept, and he competed in the match against Shelton Benjamin, Chris Benoit, Kane, Christian, and Edge. Jericho lost the match when Edge claimed the briefcase.
At Backlash on May 1, Jericho challenged Shelton Benjamin for the WWE Intercontinental Championship, but lost the match. Jericho lost to Lance Storm at ECW One Night Stand on June 12. Jericho used his old "Lionheart" gimmick, instead of his more well known "Y2J" gimmick. Jericho lost the match after Jason and Justin Credible hit Jericho with a Singapore cane, which allowed Storm to win the match. The next night on Raw, Jericho turned heel by betraying WWE Champion John Cena after defeating Christian and Tyson Tomko in a tag team match. Jericho lost a Triple Threat match for the WWE Championship at Vengeance on June 26 which also involved Christian and Cena. The feud continued throughout the summer and Jericho lost to Cena in a WWE Championship match at SummerSlam on August 21.
The next night on the August 22 episode of Raw, Jericho faced Cena for the WWE Championship again in a rematch, this time in a "You're fired" match. Cena won again, and Jericho was fired by Raw General Manager Eric Bischoff. Jericho was carried out of the arena by security as Kurt Angle attacked Cena. Jericho's WWE contract expired on August 25.
