Orton made his WWE debut on April 25, 2002. Just two months later, Cena debuted, going up against Kurt Angle on June 27, 2002. Since then, Orton and Cena's careers have taken parallel trajectories. Both have become marquee stars and world champions several times over.
Theirs is a rivalry that will not end.
Their battle to decide the undisputed champion will not be a climax, but rather another chapter in a long-running narrative of antagonism. Orton and Cena will both continue to roost on WWE's mountaintop, looking to push each other off.
It's a struggle for superiority that began even before their WWE debuts.
In the center of a ring in Louisville, Ky., Jim Cornette interviewed Orton. After twice winning the Ohio Valley Wrestling (OVW) Hardcore Championship, Orton's career was set to move from the developmental territory to the main roster.
Cornette informed the fans of Orton's promotion, and they responded with applause.
The celebration was over quickly, though. Known then as "The Prototype," Cena slipped into the ring and challenged Orton. The roles WWE fans are now used to were reversed back then, Cena playing the heel opposite Orton as a babyface.
Orton's sendoff match ended with Cena earning the victory.
In what would become an enduring rivalry, Cena went up 1-0. It wasn't long before he would join Orton in the WWE, where they would both become two of the most successful and famous OVW alums.
The two wouldn't revisit that burgeoning feud for five years.
Orton aligned himself with Evolution on his way to becoming the youngest wrestler to hold the World Heavyweight Championship. Cena went from rapping U.S. champ to the first man to ever lose the WWE Championship via Money in the Bank cash-in.
Right after Royal Rumble 2007, Cena formed a team with Shawn Michaels to dethrone Edge and Orton as tag team champions.
The Orton and Cena rivalry was only sparking at this point. It wouldn't catch fire until that summer.
Fresh off besting The Great Khali and Bobby Lashley, Cena had to contend with Orton vying for his WWE title. Cena's reign was approaching an historic length. A number of ambushes at the hands of "The Legend Killer" created a sense that perhaps it was set to end.
Orton claimed before their match at SummerSlam that, "The fairy tale, storybook ride that John Cena's been will be over."
That event would be the first of many the two would headline together. Cena kicked out of the RKO and hit the Attitude Adjustment to keep his championship.
This intensity of their feud only escalated from there. Orton would drag Cena's father out of the audience and punt him in the head.
Their rematch at Unforgiven 2007 ended with a furious Cena ignoring the referee's warnings and pounding on Orton in the corner until he was disqualified.
Who knows how violent and personal the feud would have grown from there. An injury to Cena's pectoral muscle halted that story. WWE stripped Cena of the title on Oct. 2, 2007.
The Orton vs. Cena rivalry would resume just four months later.
Cena made the most of his surprise return at the 2008 Royal Rumble, last eliminating Triple H to win the 30-man match. He challenged Orton for the WWE title a month later, the two locking horns at No Way Out 2008.
Orton survived by purposely taking the disqualification loss.
The non-decisive finish along with Triple H winning an Elimination Chamber match that night led to a Triple Threat headliner at WrestleMania XXIV.
Orton retained. A month later, it was Triple H who walked away the champion after outlasting Orton, Cena and John "Bradshaw" Layfield at Backlash 2008.
The story of Orton and Cena paused momentarily at this point.
Orton began his transformation into "The Viper," founded Legacy and won the 2009 Royal Rumble. Cena, meanwhile, feuded with Big Show, won the World Heavyweight Championship and made a surprisingly quick return from herniated disc surgery.
The two archenemies couldn't be apart for long, though.
Championships were again on the line when they met again in 2009, but there was more to their battles than ever before. Their matches grew increasingly intense, their rivalry increasingly personal.
After Orton retained against Triple H and Cena at that year's Night of Champions event, The Viper would have to fend off Cena once more in an I Quit match at Breaking Point. Orton seemed to revel in the thought of punishing Cena into submission, but Cena made it clear that the stipulation favored him.
Cena said before the match that, "when it's gut check time and your heroes are measured in heart, guess what, you're in my house because I will not quit."
During the match, Orton was the aggressor. He left Cena writhing on the floor with lacerations wrapping around his ribs. Cena hung handcuffed to the ring post, Orton delighting in his torture.
In the end, Cena won the WWE title, the first of three times the championship would change hands between them that year.
They next battled at the first-ever Hell in a Cell pay-per-view inside the unforgiving, steel structure.
Normally the Hell in a Cell provides the climax for a feud. The punt kick that Orton used to win that battle has often been the final blow to a rivalry. None of it was enough for Cena and Orton.
An Iron Man match followed.
At Bragging Rights 2009, their battle saw blood slide down Cena's head and Orton try to set his foe on fire with pyrotechnics. Cena won back the WWE title, causing the sun to set on their feud for the moment.
More than a year later, a feud between The Nexus and Cena resurrected Cena vs. Orton once more.
It began when Cena, Orton, Sheamus and Edge all clashed over the WWE Championship at Fatal 4-Way. The Nexus' interference led to Sheamus walking away champ.
Wade Barrett, who headed that new, brash group, later forced Cena to join him. The Cenation became Barrett's unwilling minion.
Soon Cena found himself in an unenviable position at Survivor Series 2010.
Cena had to serve as guest referee for the Barrett vs. Orton WWE title bout. Should Barrett win, Cena, who had been forced to be a part of Nexus, would be freed. Should Orton win, Cena would have to leave the WWE.
Even with Cena not being either champion or challenger for that match, he was the focal point. His past issues with Orton became the subplot to the main story centered around The Nexus.
Those are issues that WWE wouldn't revisit in earnest for another three years.
After Orton denied Big Show's quest for the WWE Championship at Survivor Series 2013, Cena entered the ring carrying his World Heavyweight Championship. The two champs faced off, giving fans a preview of what would eventually be announced as a title unification match.
WWE did well to remind us in the next few weeks just how much violence comprised these two men's history.
Images of Orton punting Cena's father, of him handcuffing Cena, of the many championship battles they've had came rushing back into the forefront of fans' brains. Hell in a Cell, Iron Man matches, submissions and knockouts couldn't decide this rivalry for good, and likely, neither will the TLC match set for Dec. 15.
The intensity that these men have together is just too strong. That was on display when Orton and Cena signed the contract for the TLC bout.
The brawl that followed reminded us of just why WWE has gone back to this feud so many times. Just like with Vince McMahon and Steve Austin, Kane and Undertaker, there is seemingly always some electricity left to siphon from Orton and Cena's bad blood.
Years may pass in between their collisions, but as history has told us, we can expect these two men to trade punches until they both retire.
TLC is the latest, not the final, act in a drama that was born in 2002 and refuses to find its resolution.