20 of World Football's Greatest Rivalries
Rivalries are a big part of any sport, and football is no different.
No matter which team you support, your club more than likely has at least one fierce rival. Or maybe two or three. You know who we mean: The team you just can't stand, the team you just can't stand losing to.
Because of the global nature of football, those kind of rivalries are all over the world. In this slideshow, we pick 20 of the biggest. Almost any list like this is subjective, but we generally tried to go with rivalries that are long-lived and have historically high stakes.
Keep reading to see who made the cut.
This weekend, the red and blue halves of Merseyside will face off again as Everton host Liverpool at Goodison Park.
The rivalry dates to 1892, when the Reds split off from the Blues, and over the years each club has enjoyed its share of success.
While not as bitter as some other rivalries in England, both sides give it their all every time they renew acquaintances.
Real Madrid-Atletico Madrid (Spain)
With Atletico Madrid's return to prominence, their rivalry with Real Madrid has taken on renewed importance in recent seasons.
The two capital clubs met in the 2014 UEFA Champions League final, with Real coming from behind to win La Decima.
And with both teams fighting for silverware on multiple fronts, there have been several excellent matches for fans to enjoy. As ever, the teams have exhibited full commitment and intensity when facing off against each other.
Arsenal-Tottenham Hotspur (England)
It's no secret that fans of Arsenal and Tottenham Hotspur dislike each other.
The two sets of supporters will take any opportunity to troll the other, regardless of whether they're actually playing in the same game.
The rivalry began in 1887, and though both teams have seen success, Arsenal have generally enjoyed the upper hand in recent years.
Manchester United-Liverpool (England)
Manchester United and Liverpool are the two most successful clubs in English football, and they're also located fairly close to one another.
It's no surprise, then, that the players, fans and even the cities don't like each other at all.
Liverpool long held the record for most league titles in England, but when United overtook them it was no coincidence that it happened while the Red Devils enjoyed a good run in the rivalry.
Barcelona-Real Madrid (Spain)
When Barcelona and Real Madrid contest El Clasico, the world stops to watch.
The two most-successful teams in Spanish history always put on a good game, and more often than not, there will be fireworks.
Both Barca and Real have huge budgets, so both clubs regularly field many of the world's best players. That often makes for a brilliant level of play in what is one of the world's most-heated rivalries.
Ajax are the most-successful club in Dutch football history, having won 33 league titles. Feyenoord are third with 14. Their rivalry is unsurpassed in the Netherlands.
When the two clubs play each other in De Klassieker, the stakes are almost always high. And it's not just about the clubs. Amsterdam and Rotterdam are the two biggest cities in the country, and the two could hardly be more different culturally.
Athletic Bilbao-Real Sociedad (Spain)
Regional identity is fiercely important in Spain's Basque country, so it makes sense that the region's two clubs have a strong rivalry.
Both Athletic Bilbao and Real Sociedad have had policies of fielding only Basque players in the past, but Sociedad aren't quite as strict about it today.
Athletic still follow their policy, though, and it's served the club well recently.
Paris Saint-Germain vs. Marseille (France)
It's called "Le Classique," and the rivalry between Paris Saint-German and Marseille often produces classic matches, as the name would suggest.
The two sets of fans come from France's two largest cities, and as we'll see throughout this list, they don't care for each other much.
The hatred has unfortunately gone too far on occasion, however. In 2010, a PSG fan died after violence broke out between the two clubs' supporters.
Matches in the Fla-Flu rivalry take place in the Maracana Stadium, home to two World Cup finals (technically one was just the final game of the World Cup, but still) and site of many decades' worth of great football.
The games between the Rio de Janeiro rivals, Flamengo and Fluminense—two of Brazil's biggest clubs—are always well attended, with more than 194,000 witnessing a game between the two in 1963.
Legia Warsaw-Wisla Krakow (Poland)
Krakow was Poland's capital for more than 500 years, but in 1596, King Sigismund III Vasa moved his court from Krakow to Warsaw and a rivalry was born.
Well, not really, but the historical division between Warsaw and Krakow dates to at least that time.
In modern times, Poland's two most-successful clubs are Legia Warsaw and Wisla Krakow. Whenever the two meet, there's a historical edge to the rivalry.
Manchester United-Manchester City (England)
The red and blue halves of Manchester have never liked each other, but now the rivalry has even higher stakes.
Through the years, matches between United and City were always fierce as the two fought for local bragging rights.
But thanks to City's recent rise to prominence, the "noisy neighbours" are now challenging (and lately beating) their rivals for domestic silverware.
Meanwhile, the fans still dislike each other.
Boca Juniors-River Plate (Argentina)
Boca Juniors and River Plate are the two biggest clubs in Argentina. Both come from Buenos Aires, and both have a long history of success.
Naturally, then, the fans of one can't stand the other. But when the two teams play, the supporters always create a brilliantly intense atmosphere.
Speaking of intense atmospheres, Galatasaray's former ground, Ali Sami Yen Stadium, was commonly known as "Hell." The club's current digs, the Turk Telekom Arena, aren't quite the same, but Gala fans can still make any visiting team feel unwelcome.
At the top of their list is Fenerbahce, Gala's biggest rivals. The two successful Turkish clubs contest the Intercontinental derby, so named because Gala sit on the European side of the Bosporus and Fener on the Asian side.
What other rivalry can claim that?
The financial demise of Rangers has stripped the Old Firm rivalry of its prestige in recent years.
In fact, Celtic and Rangers haven't met in the Scottish league since 2012, the year Rangers were relegated to the fourth tier following liquidation of the club.
Even so, the Old Firm is one of the fiercest rivalries in the world. Celtic and Rangers are more than just rivals on the pitch.
The clubs both come from Glasgow, but they are different ideologically and their fans are divided largely on religious lines.
They're also the two most-successful clubs in Scotland, so once Rangers find a way back to the top flight, the rivalry will resume in earnest.
Rome is the Eternal City, and the Italian capital's two biggest clubs, Roma and Lazio, will forever be rivals.
Clashes between the two have unfortunately witnessed fan violence, and the atmosphere on the pitch is always intense.
Partizan Belgrade-Red Star Belgrade (Serbia)
Rome is the eternal city, but Partizan vs. Red Star is the Eternal Derby of Belgrade.
The two clubs sit literally yards apart from each other in Serbia's capital city, and the matches frequently produce some of the most intense atmospheres in world football.
The Milan derby hasn't held its usual importance in recent seasons. For much of their histories, AC Milan and Internazionale have competed for trophies domestically and in Europe. But a downturn in results has seen both clubs drop out of European competition this term.
Even so, when Milan play Inter at the San Siro, it's must-see television throughout Europe and beyond.
With such proud traditions, it's only a matter of time before the Rossoneri and Nerazzurri are back to their best.
Borussia Dortmund-Schalke (Germany)
Borussia Dortmund and Schalke are local rivals from the Ruhr region of Germany. Fans of both sets of teams generally can't stand each other.
So, just how important is the rivalry to both sets of supporters?
"The folk here in the Ruhr Valley live for and love this match," former Schalke general manager Rudi Assauer said, per FIFA.com.
Sporting and Benfica are two of the three Portuguese clubs that have never suffered relegation from the top flight (Porto being the other).
That means the sides from Lisbon have had a long time to build up a heated rivalry, and they've done just that.
Benfica have the upper hand, claiming 34 league titles to Sporting's 18. But every time the two sides play, you can throw records out the window.
Greek sides Panathinaikos and Olympiakos contest the 'Derby of the Eternal Enemies', a fantastic name that sums up the rivalry well.
Panathinaikos is located in the centre of Athens and thus the club represent the high culture of the ancient city. Olympiakos come from Piraeus, Athens' port, and represent a more working-class demographic.
It won't be any surprise, then, that the two sets of fans really dislike each other. Violence has marred the rivalry in the past, with supporters clashing when the clubs meet in other sports as well, like volleyball and basketball, per BBC Sport.
Where geography and society left off, football took over. Panathinaikos and Olympiakos are Greece's two most-popular sides, and both have a history of success. Olympiakos hold the edge with 42 league titles to Panathinaikos' 20.