Did you know that the Intercontinental Championship was once unified with the World Heavyweight Championship? Or that the WCW Tag Team Championship and WWE World Tag Team Championship were unified on two separate occasions three months apart?

Following WWE's acquisition of WCW in 2001, there was an influx of championships from the Atlanta-based organization. Over the following two years, WWE’s title scene went through more changes than it ever had in the company’s history. In total, seven championships were retired, two were reinstated and two were created completely from scratch.

If you were a WWE fan during this “Era of Unification,” you might recall some of the convoluted events that brought these titles together and then tore them apart. Still, WWEClassics.com spent weeks attempting to untangle the complex history of this landmark period. By the time we were done with our research, our heads were spinning and our eyes were glazed over from pouring through Titan Towers’ record books. Thankfully, we think we finally have this highly complicated age in sports-entertainment history figured out.

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Watch the "Era of Unification" unfold |  View photo gallery | Explore Title Histories

The unification of the WWE Light Heavyweight Championship and WCW Cruiserweight Championship

The first attempt to condense the number of titles in WWE did not go quite as easily as planned. On the July 30, 2001, edition of Raw, X-Pac, the WWE Light Heavyweight Champion, defeated Billy Kidman, the WCW Cruiserweight Champion, to unify the two titles. X-Pac lost the Light Heavyweight Championship to Tajiri on the very next edition of Raw, but unified the titles once again by defeating The Japanese Buzzsaw at SummerSlam.

The championships were united for nearly two months until Billy Kidman regained the Cruiserweight Title and then promptly lost it to Tajiri. The intense grappler from the Far East was set to face X-Pac to merge the titles once and for all at Survivor Series, but X-Pac went on the shelf with an injury and the bout was canceled. When WCW disbanded following Survivor Series, X-Pac’s Light Heavyweight Championship was abandoned in favor of Tajiri’s Cruiserweight Title – a championship with a significantly richer lineage – which adopted the WWE name.

The unification of the WWE Intercontinental Championship and WCW United States Championship

After the Light Heavyweight/Cruiserweight debacle, the next attempt at streamlining the championship picture went far more smoothly.

Survivor Series 2001 was presented as a “Winner Take All” event, and was the official ending to the Invasion that had dominated WWE throughout the summer and autumn. Two weeks before the event, Edge – the recently crowned King of the Ring – lost the WWE Intercontinental Championship to Test on Raw. One week later, Edge won the WCW United States Championship and then defeated Test at Survivor Series to unify the titles.

With WCW’s demise at the event, the 26-year-history of the United States Championship was retired in favor of WWE’s Intercontinental Title. But as much of the WWE Universe knows, that was not the last time fans would see the United States Championship.

The unification of the WWE World Tag Team Championship and WCW Tag Team Championship

The attempts to unify each organization’s tag team championship proved to be nearly as difficult as the merging of the Light Heavyweight and Cruiserweight Championships.

The Undertaker & Kane won the WCW Tag Team Championship on the Aug. 9, 2001, edition of SmackDown. On the same night, WCW competitors Diamond Dallas Page & Kanyon defeated The APA to become WWE World Tag Team Champions. The two new titleholding teams met in a Steel Cage Match at SummerSlam to rectify this bizarro universe by unifying the titles.

The Brothers of Destruction emerged victorious at SummerSlam, but soon lost both sets of titles to individual teams. Over the following two months, the WWE World Tag Team Championships were briefly carried by the odd couple tandem of Chris Jericho & The Rock, and both sets of titles were held by the teams of Booker T & Test, The Hardy Boyz and The Dudley Boyz.

Finally, The Dudleys defeated their longtime adversaries The Hardy Boyz in a Steel Cage Match to unify the championships at Survivor Series . Bubba and D-Von are the only tag team in history to hold the titles of the three major sports-entertainment organizations – WWE, WCW and ECW.

The unification of the WWE Championship and WCW Championship

The most significant unification of this period was a moment that Chris Jericho won’t let anyone forget. One month after WCW was officially defeated at Survivor Series, the WCW Championship and the WWE Championship were arranged to finally be unified at Vengeance in December 2001.

A mini tournament was orchestrated to make matters as fair as possible. In the first bout, WWE Champion “Stone Cold” Steve Austin retained his title against Kurt Angle, and earned the right face the winner of the WCW Championship Match between Chris Jericho and The Rock.

Jericho defeated The Brahma Bull to win the title and was immediately faced with the task of battling Austin for the WWE Championship. Y2J emerged victorious – thanks to a bit of assistance from Mr. McMahon – and earned the right to brag that he is “the best in the world at what he does” by defeating two of sports-entertainment’s most iconic stars in one night.

After Jericho was defeated by Triple H at WrestleMania X8 , the two titles were merged into the WWE Undisputed Championship. Ric Flair did the honors of presenting The King of Kings with the brand new title on the April 1, 2002, edition of Raw.

The unification of the Intercontinental, European and Hardcore Championships

As WWE began to put the Attitude Era in the rear-view mirror, two of the championships that defined the period were put to rest in summer 2002. And the man that responsible for the mergers was Rob Van Dam.

With Eric Bischoff’s first order of business as the General Manager of Raw, Intercontinental Champion Van Dam was ordered to face off with European Champion Jeff Hardy to unify those two titles on the July 22 edition of Raw. True to his moniker, Mr. Monday Night defeated Hardy in a Ladder Match and the European Championship was retired.

Discover the unique story of the Europen Title

The following month, RVD battled Hardcore Champion Tommy Dreamer in what was billed at the time as the last-ever Hardcore Match in WWE. The two ECW icons made the most of it and competed in a brutal bout that saw The Whole Dam Show once again emerge victorious. The Hardcore Championship was retired to close out the history of perhaps WWE’s most bizarre title.

The creation of the World Heavyweight Championship

At SummerSlam 2002, Brock Lesnar defeated The Rock to win the WWE Championship and become the youngest champion in the title’s illustrious history. At that time, the WWE Champion could compete on both the Raw and SmackDown brands. But following Lesnar’s victory, SmackDown General Manager Stephanie McMahon declared that the new champion’s contract only required him to appear on the blue brand.

With Lesnar refusing to show up on Raw, it left WWE’s flagship broadcast without a champion. That void was quickly filled by Raw General Manager Eric Bischoff. One week after SummerSlam, Bischoff opened a briefcase in the ring and revealed a title that many fans recognized as the WCW Championship. He called the title the World Heavyweight Championship and awarded it to Triple H, who had  defeated The Undertaker the previous week to become the No. 1 Contender to Lesnar’s championship.

While the World Heavyweight Championship was a new title, it is widely regarded as the successor to the NWA and WCW Championships, whose “Big Gold” style was commissioned by wrestling promoter Jim Crockett in 1985.

The creation of the WWE Tag Team Championship

After the World Tag Team Championship – with its history dating back to 1971 – became exclusive to Raw, SmackDown was left without a championship for its tag team division. To encourage tag team competition on her show, SmackDown General Manager Stephanie McMahon introduced the WWE Tag Team Championship, represented by titles emblazoned with the bright blue color so associated with SmackDown’s look.

Stephanie declared that the inaugural champions would be decided via an eight-team tournament to be held on SmackDown throughout October 2002. The two teams who advanced to the finals would compete at No Mercy to become the first WWE Tag Team Champions.

The competition featured a number of unique tandems including the duos of Reverend D-Von & Ron Simmons, Brock Lesnar & Tajiri, Mark Henry & Rikishi and the dynamic team of Edge & Rey Mysterio, who fell in the finals at No Mercy.

Watch Edge and Mysterio battle the mismatched pair of Lesnar and Tajiri

The unification of the World Heavyweight Championship and Intercontinental Championship & reinstatement of the Intercontinental Championship

Crowning the first WWE Tag Team Champions was not the only notable championship occurrence to take place at No Mercy. On Sept. 30, 2002, Raw General Manager Eric Bischoff announced that Triple H’s World Heavyweight Championship would be unified with Chris Jericho’s Intercontinental Championship at No Mercy. But first, each would have to defend their titles on that night’s edition of Raw.

Triple H was victorious in his matchup against Bubba Ray Dudley, but Jericho lost the Intercontinental Title to Kane . The Game then defeated The Big Red Monster at No Mercy to unite the titles, but the Intercontinental Championship did not disappear for long.

Only seven months after it was retired, the Intercontinental Championship was reinstated by co–General Manager “Stone Cold” Steve Austin on the May 5, 2003, edition of Raw. Revealing the retired title by pulling it out of a sack, Austin declared that the championship’s vacancy would be filled in a Battle Royal at Judgment Day. The bout was won by Christian, and the Intercontinental Championship has continued to be one of WWE’s most heralded titles.

The reinstatement of the United States Championship

Stephanie McMahon was a very busy SmackDown General Manager. Less than nine months after creating the WWE Tag Team Championship, The Billion Dollar Princess declared she was bringing back the United States Championship to encourage competition among the rising stars of her show. No longer carrying the initials of WCW, the WWE United States Championship would adopt the rich lineage that had been temporarily halted at Survivor Series 2001.

A tournament was held on SmackDown throughout June and July of 2003 to fill the title’s year and a half vacancy, and featured Superstars like Billy Gunn, John Cena, Ultimo Dragon and Rikishi. Eddie Guerrero came out on top in the finals at Vengeance and was crowned the new United States Champion. Stephanie’s decision was a good one – the title has been hotly contested ever since.

Watch Eddie Guerrero square off against Ultimo Dragon

The continuing evolution of WWE's championships

As WWE entered the second half of 2003, the championship picture began to stabilize for the first time in many years. Seldom have major changes been made to the championships defended in WWE since the “Era of Unification.”

In July 2007, Hornswoggle shockingly won a Cruiserweight Open to become the new Cruiserweight Champion. Two months later, Vickie Guerrero forced Hornswoggle to vacate the title on her first night as General Manager of Smackdown and the Cruiserweight Championship has never been seen again

Investigate the strange cases of seven missing titles

At WrestleMania XXV in 2009, WWE Tag Team Champions Primo & Carlito defeated World Tag Team Champions John Morrison & The Miz in a Lumberjack Match to unify the titles. For more than a year, the Unified Tag Team Champions – as they were referred to – would collectively carry around all four titles. But on the Aug. 16, 2010, edition of Raw, Bret “Hit Man” Hart presented reigning champions The Hart Dynasty with brand-new titles with a bronzed Spartan-inspired look. The titles have been referred to as the WWE Tag Team Championships ever since, bringing an end to the nearly 40-year history of the World Tag Team Titles.