Without derbies the sport wouldn't be the same and the soccer world contains many rivalries in every corner of the globe. Whether the hatred for the other team is purely geographical or whether there are different reasons for the rivalry, here at Planet Sport we look at some of the fiercest derbies and why they're so important for the teams involved.
What is a derby?
Firstly, the question needs addressing to identify what is actually meant by a 'derby'. Simply, a derby is a grudge match between two clubs for geographical reasons, as is the case in many derbies or a historical feud which caused a rivalry - or even a combination of the two.
To the fans who support a team involved in a derby, the event is seen as the most important game of the season and one that the supporters look for first when the fixtures are released. Fans and players want bragging rights over the other team and will go to great lengths to secure a victory. Winning is everything in these clashes.
Barcelona vs Real Madrid
Separated by over 600km, location is not a factor in the rivalry, but politics is. Real is seen as representing nationalism because the Spanish government is based in Madrid. In contrast, Barcelona show Catalan nationalism, emphasising the idea they want independence from Spain.
With completely contrasting political ideas, the fierceness of the rivalry starts with the fans. Players have moved between the two giants, albeit rarely, and consequently faced backlash from supporters as moving to a rival is severely frowned upon.
In recent years, Barcelona versus Real Madrid has been viewed by many across the world as Lionel Messi versus Cristiano Ronaldo, until the Portuguese superstar moved to Juventus. The hype around the matches, whether in the league, cup or in the UEFA Champions League, meant hundreds of millions of people tuned in to watch the battle on the pitch.
Liverpool vs Manchester United
The battle of the north-west has gained prominence as one of the most brutal and keenly contested since the inception of the Premier League in 1992. It is considered the most passionate sporting event in the world because both teams have such a large following across the globe.
This derby is so important to the soccer world that it is considered to hold greater significance than the two clubs' local derbies (with Everton and Manchester City respectively). Encounters on the pitch when the two teams face off emphasise the magnitude of the derby. Watch any highlights of a Liverpool and Manchester United game and you will likely see red cards, brawls and passionate fans vying for bragging rights.
A rivalry based on industrial and economic factors, the two cities divided by 55km, have always been in close competition on the pitch. Liverpool and Manchester United are the two most successful teams in the history of English football, and regarding trophies they are now neck-and-neck, making the rivalry that little bit more tasty.
Celtic vs Rangers
Known globally as The Old Firm, this derby is one of the greatest in the world. Celtic and Rangers are both clubs based in the Scottish city of Glasgow, and are by far the two most well-known teams in the country.
Between them they have won over 100 Scottish League championships, showing their sheer dominance of the domestic scene and the fight for the title is usually a two-horse race.
Although the definition of the name given to the derby is not factually known, it is believed that they were originally called 'two old, firm friends' by commentators. Initially friends as opposed to foes, the two clubs over time have grown further and further apart, resulting in the famous Old Firm derby.
The history of the rivalry features disputes over religion, Catholic versus Protestant, and national identity, Irish Scottish versus British. The hatred between the two sets of fans is so strong that in the past it has seen many cases of violence, some of which has resulted in death.
Boca Juniors vs River Plate
Regarded by many as the number one fiercest derby in the world is the battle of Argentinian clubs Boca Juniors and River Plate. Appropriately named, the Superclasico has been played over 250 times and the fans of the two teams account for around 70% of all football fans in the country of Argentina.
Both clubs are based in Buenos Aires and have two of the biggest and best stadiums in the world. Going to see the match itself is viewed as a once-in-a-lifetime opportunity. The competitiveness of the rivalry, alongside the threat of danger, is reflected by the 2,000 policemen and security deployed to keep unrest and violence to a minimum.
The rivalry between Argentina's most successful clubs has had its fair share of violence in the past. In 2015, fans tear gassed opposition players leading to the match being abandoned and some players having to go to hospital as a result.
Three years later, the two teams were due to meet in the second leg of the Copa Libertadores final. However, River Plate fans attacked the Boca team bus on its way to the stadium and players again were injured. In a bold move highlighting the threat of holding the game in Argentina, the match was moved to be played in Madrid.
AC Milan vs Inter Milan
These two teams share the same ground, San Siro, and both teams want to say they are the best team to play on that pitch. Although there are many fierce derbies in Italy, Derby della Madonnina is seen as the biggest.
This derby originated from a social divide between fans. Some stakeholders in AC Milan wanted to sign foreign players and when they didn't get their wish, they created a new club: Internazionale, or more commonly known as Inter Milan.
The breakaway meant that Italy's two biggest teams were playing in the same stadium, something that is not too common, meaning that it is an intriguing clash whenever the two giants meet.
Perhaps one of the most notable Milan derbies was in 2005 when during a Champions League match, AC Milan goalkeeper Dida was struck by a firework thrown at him by Inter fans. The game was abandoned after 73 minutes after Inter fans continued to throw flares and bottles from the stands onto the San Siro pitch.
Nacional vs Penarol - Uruguay's biggest rivalry and it has all the ingredients to be the perfect derby. History, amazing stadiums and recent controversy are among some of the highlights.
Lazio vs Roma - Similar in size and style to the AC Milan v Inter Milan derby as two capital city rivals do battle - also sharing the same stadium.
Fenerbahce vs Galatasaray - Flares, riots and passion, Turkey's main event of the calendar is always this clash.
Olympiacos vs Panathinaikos - Known as the Derby of Eternal Enemies, the nature of this fierce derby in Greece has plenty of history.
East Bengal vs Mohun Bagan - Perhaps not as widely heard of as the other rivalries, but this Indian match-up between two teams who share the same stadium is massive. All because one of the teams' decided not to pick a player, a whole new club was formed and a rivalry began.