Alex Brandon/Associated Press

Eagles center Jason Kelce's speech at the team's Super Bowl parade in Philadelphia was unforgettable. While donning a feathered Mummers costume, he went full Ric Flair, bashing the national media that doubted his team and using colorful language that made the team officials sharing the stage with him blush.

At the end of his electric four-and-a-half-minute rant, a hoarse Kelce led the massive crowd in singing a song popularized by fans of the city's Major League Soccer team, the Philadelphia Union. He said he'd heard it for the first time earlier that day, while pounding beers with fans along the parade route. (Warning: NSFW language.)

"No One Likes Us, We Don't Care" perfectly encapsulates the essence of the Philly fan—brash, unapologetic and with an underlying inferiority complex that simultaneously fuels pride and defensiveness. Growing up in the shadow of New York, Philadelphia doesn't have the championship pedigree of its big brother to the north. Hell, the Eagles' Super Bowl LII victory was just the city's second major pro sports title since Ronald Reagan's second term as president.

"Our city kind of sucks sometimes," said Shamus Clancy, a lifelong supporter of the Eagles and a native of South Philly. "The weather stinks. The two seasons are freezing rain and unbearable humidity. Outsiders think we're dumb and talk like idiots. We're classless, apparently. But on a fall morning, when the weather is perfect for the archetypal long-sleeve-shirt-and-shorts Philly outfit, and the Eagles are playing at the Sports Complex, where in the world would you rather be?''

If you know the history of "No One Likes Us, We Don't Care," which dates back nearly a half-century, it's fitting that it ended up as the rallying cry for the Super Bowl champion Eagles.

The chant originated with Millwall FC, a club that has spent the majority of its 133-year history bouncing between the second and third tiers of English soccer. One of a dozen professional teams located in London, Millwall doesn't have the cachet of neighbors Chelsea, Tottenham Hotspur and Arsenal. Like Eagles fans, their supporters channel that underdog mentality into a "f--k you" attitude that draws the ire of the football community at large.

But while throwing snowballs at Santa is the darkest mark on Eagles fandom, Millwall's history is dotted with a far more sinister set of incidents. During the first half of the 20th century, the club was forced to close its home grounds multiple times due to violent behavior from its supporters.

In the 1960s, one fan threw a hand grenade onto the pitch during a road match against crosstown-rival Brentford. (Luckily, it didn't go off.) And throughout the '70s and '80s, the much-maligned Bushwackers hooligan firm engaged in increasingly destructive behavior to the point that Millwall chairman Alan Thorne briefly threatened to terminate the club in 1982.

If Americans find Philly fans obnoxious and classless, English soccer fans view Millwall supporters as borderline criminal.

Richard Heathcote/Getty Images

"Some negative events are often exaggerated when we're involved, and the Millwall fans feel that we are often singled out whenever the subject of football hooliganism is brought up," Michael Avery, who helps manage the Millwall Supporters Club, said. "The club's former chairman, Reg Burr, once said that 'Millwall is a convenient coat-peg for football to hang its ills on,' and 'No One Likes Us, We Don't Care' represents this. Rightly or wrongly, Millwall's reputation means we are often painted in a bad light."

No-one likes us,

No-one likes us,

No-one likes us,

We don't care!

We are Millwall,

Super Millwall,

We are Millwall,

From The Den!

Millwall supporters sing their version of the song to the tune of Rod Stewart's 1975 hit "Sailing," and they sing it often—at the pub before the match, on the ride to their stadium (affectionately referred to as The Den), at the gate entering the grounds, before the opening whistle, after bad calls, after good calls, after wins and even sometimes after losses.

But in recent years, the club's fans have settled down some, in part because of an increasing commercialization of the sport that has led to a diversification of the club's fanbase. And while Millwall's blue-collar reputation remains, the South East London neighborhood from which its supporters are primarily drawn has traded shipbuilding for craft brewing in the 21st century.

There's an obvious parallel between Philly fans and Millwall supporters. From their shared working-class roots and subsequent gentrification to their tongue-in-cheek sense of humor, their violent past and enduring reputation in the present, the two are in a way unknowingly and unintentionally intertwined.

"We have tried to fight being the heel for a while now, but as Jason Kelce said, 'f--k 'em,'" John Barchard, a lifelong Eagles fan and the host of the BGN Radio podcast, said. "If people fear coming into Lincoln Financial Field to play the Eagles, good. You want to say we're a bunch of gang members? Fantastic. You want to say we are the worst fans in the world? Even better. I don't want you to feel comfortable at all wearing that ugly-ass Giants jersey at The Linc. ... The beauty is that the energy from the Super Bowl win is spreading over to the Sixers and Flyers. If they go on deep playoff runs, the pettiness will be an all-time high, and I welcome every moment of it."

Alex Brandon/Associated Press

The story of how "No One Likes Us, We Don't Care" crossed the Atlantic and found a home in Philadelphia is peculiar.

In January 2007, a group of a dozen or so Philly-based soccer fans who met on the internet forum BigSoccer.com got together for the inaugural meeting of the Sons of Ben (as in Franklin). The group quickly became the unofficial supporters group of a Major League Soccer club that didn't yet exist and wasn't publicly in the works at that time.

Yes, you read that correctly. Philly fans are so fanatical that they created a supporters group for a sport that didn't exist in their city and basically willed a team into existence through sheer grit and determination, using the success of the group to prove to investors that Philadelphia was an untapped market for MLS.

Since there weren't actual matches to go to during the early days of the SOB—the acronym is most certainly intentional—the group would travel to games in other cities as well as various league events and generally make fools of themselves. They'd make up Philly-based chants, poke fun at the supporters of other clubs and implore the league to grant to them a team.

Opposing fans didn't take kindly to a bunch of randos from a city that didn't have a team invading their stadiums and relentlessly trolling them, and it wasn't long before a Philly-oriented version of "No One Likes Us, We Don't Care" organically came to prominence after the city acquired an expansion franchise in 2008. Their version was set to the more widely known tune of "Oh My Darling, Clementine" and was lyrically altered to remove the references to Millwall's home stadium.

No one likes us,

No one likes us,

No one likes us,

We don't care!

We're from Philly,

F--king Philly,

No one likes us,

We don't care!

"Soccer fans borrow chants and songs from each other all the time, so we tweaked the Millwall song a little bit and made it our own," Corey Furlan, one of the original members of the Sons of Ben and a lifelong Philly sports fan, said. "Once we got the team, when we'd go to other cities for games fans of other teams would kind of just go, 'Oh look, here are those assh--es from Philly again.' ... At a gut level, I really don't care what people from Kansas City or New York or D.C. or anywhere think. We just go to matches, and we are who we are."

Drew Hallowell/Getty Images

Today, the Sons of Ben have about 3,000 active members, and the Union will celebrate their 10-year anniversary this season. "No One Likes Us" remains a staple at the team's matches, and it now has found new life with the Eagles. The versatility of the SOB version of the song, which replaces the name of the club with the name of the city and removes any team-specific elements, makes it a chant that could easily take hold among fans of all five of the team's major professional teams.

Furlan says he'd be just fine with that, although he knows some purists who root for the Union might take offense.

"There are a lot of our fans who call the NFL 'hand egg' because they don't think it's real football. And it's like, bro, you're from Philly, not Millwall," he said. "Most were pretty excited about Jason Kelce using the song, though. It was so cool seeing him at the parade singing it on the Art Museum steps with a million people chanting along. To see it go mainstream like that was amazing. ... I would love to hear 70,000 Eagles fans do the chant at a home game. It would be unbelievable."