One is a big, beef-eating strongman from Massachusetts who’s goofy and gritty in equal measure, with a personality as clean-cut as his Dudley Do-Right jawline. The other is an undersized, hairy, vegan grappler from Aberdeen, Wa., whose face is as scraggly as a Wild Thing and who mainly communicates in one-word responses at earsplitting volume. And at SummerSlam, John Cena and Daniel Bryan are going to beat the hell out of each other with the WWE Championship at stake.

It’s a main-event matchup the WWE Universe has dreamt of, but never thought it would see: the big-hearted standard-bearer battling the ferocious underdog who, as he’s happy to tell you, was never entirely sure he’d make it to the dance in the first place. The career trajectories of John Cena and Daniel Bryan are so different they seem to have come from different planets, but ironically, the two SummerSlam combatants have been orbiting each other for 10 years.

Before Cena and Bryan meet for all the marbles at the summer classic, step back and walk the long, strange path that led them here.

A taste of things to come

Two future World Champions square off on Velocity.

These days it’s tough to imagine John Cena and Daniel Bryan as anything other than World Champion-caliber Superstars, but a full ten years before their SummerSlam main event was made, the two squared off as hungry up-and-comers on WWE Velocity. Though Cena was already a tenured – if only briefly – Superstar and Bryan merely a clean-cut (and beardless!) prospect, the two put on a gritty contest that showed flashes of the main-event warriors they’d one day become. It was Cena who ultimately prevailed in the brief tilt, though any student of the game could see that big things would eventually spring from both participants of that humble little match.

Watch other great Velocity matches

“YOU ARE NOT BETTER THAN ME!”

Nearly a decade after first tussling with the Cenation jefe on Velocity, Bryan found himself with a foothold in WWE as The Miz’s protégé in the first season of WWE NXT. Bryan’s stint under The Awesome One’s tutelage seemed to hint at the personality of a clean-cut brawler, yet the self-styled “American Dragon” truly bared his claws when he debuted alongside his fellow newbies in the ranks of The Nexus. Storming the ring at a 2010 “Viewer’s Choice” edition of Raw, the NXT interlopers laid waste to both Cena and CM Punk – who were competing at the time – before dismantling the ring and attacking the commentary team in one of the most brazen debuts in WWE history.

Watch:  Bryan and Miz butt heads on NXT |  Rookie Bryan faces World Champion

Bryan played a pivotal part, screaming and spitting in The Champ’s face before fulfilling the famous threat from the his pre-WWE days and kicking Cena’s head in. In any ordinary story, this may have been the ending point. But this isn’t any ordinary story, and Bryan’s long, strange dance with The Champ was far from complete.

… You’re against us

Daniel Bryan makes a surprise return to WWE at SummerSlam 2010

Bryan’s subsequent remorse over the ambush got him excommunicated from The Nexus, and the brutality with which he carried it out briefly got him fired from WWE altogether. The group carried on without Bryan just fine, though, besieging the WWE locker room and carrying out random, vicious strikes over the course of the next month. Among other consequences, these attacks led Cena to lose his WWE Championship to Sheamus at the Fatal 4-Way pay-per-view and the beating perpetrated on then-Raw GM Bret Hart was so severe Mr. McMahon had to relieve the “Hitman” of his duties and replace him with the Anonymous Raw GM.

Tensions ultimately built to a head at SummerSlam, where The Nexus was slated to face an All-Star “Team WWE” squad captained by The Cenation leader in an Elimination Tag Team Match. After the group took out The Great Khali, Cena’s ranks were left short a man heading into the tilt. Happily, there was a replacement ready and waiting: Daniel Bryan. Riding the wave of Bryan’s defection, Team WWE ultimately prevailed, with Cena standing tall as the sole survivor.

Bragging rights

John Cena and Daniel Bryan go one-on-one for the first time ever on Raw.

Fast forward two years from that fateful SummerSlam and Bryan had gone into business for himself, a scraggly egomaniac recently removed from a World Heavyweight Championship reign (and three attempts at the WWE Title) who spoke mostly in affirmative/ negative interjections. Cena, meanwhile, had not been WWE Champion for nearly a year and was in the midst of a long slog back to the top following his loss to The Rock at WrestleMania XXVIII.

With nothing on the line but pride on a hot August Raw, the two veterans had it out in a plus-sized update of their fateful Velocity bout nine years earlier. Yet for all of Bryan’s brash aggression, the result remained the same when Cena defeated the submission master with an Attitude Adjustment for three.

Contain the “Hounds”

WWE Champion John Cena and WWE Tag Team Champions Team Hell No work together to face The Shield in the main event of Raw.

After WrestleMania 29, both Bryan and Cena had finally found glory once again – Cena as WWE Champion after dethroning The Rock in a rematch of their 2012 bout, and Bryan as one-half of the dysfunctional-yet- dominant WWE Tag Team Champions, Team Hell No, alongside Kane. But one of their biggest triumphs would come, once again, not as individuals, but as members of a superteam.

Photos: Cena finds redemption |  Bryan's "YES!"-tleMania

The WWE locker room had long been faced with a problem in a new trio of NXT alumni known as The Shield, three like-minded warriors with a twisted sense of justice who had yet to suffer a defeat as a group. A few weeks after WrestleMania, Cena and Team Hell No were slated to face The Shield in Six-Man Tag Team action. Although Cena was slightly tripped up by a gimpy Achilles tendon, the super-trio managed to hand The Shield their first defeat on Raw. Granted, it was a Disqualification win that the "Hounds of Justice" willingly accepted for the sake of beating on The Champ, and Cena did end up worse for wear when he was planted with a ruthless Triple Powerbomb. Still, a win is a win.

Watch:  The Shield's most monstrous Triple Powerbombs

This, of course, brings us to …

SummerSlam showdown

The WWE Championship Match is set for SummerSlam with John Cena defending against Daniel Bryan.

… Now.

Although Bryan failed to capture the WWE Title Money in the Bank Contract that ended up in Randy Orton’s hands, his winning streak in the wake of Team Hell No’s loss of their titles did not go unnoticed by Cena. So when The Champ was afforded the opportunity to select his own SummerSlam opponent by new Raw GM Brad Maddox, naming Bryan was something of a no-brainer.

Whether Bryan can upend Cena remains to be seen, but either way, the WWE Universe should be in for a bona fide classic when these long-passing ships finally trade fire.