There isn't a lover of football who doesn't know just how intense the rivalry is between Barcelona and Real Madrid, but few realise that it was not always rooted in sports. The conflict between the two Spanish giants has spanned the last 80 years and has had heavy influence both politically and economically.
The 20th century witnessed a notable footballing feud grow between the two sides, and the world watched as a 1943 Copa semi-final became one of the most defining games in the history of El Clasico, as Real Madrid won the game 11-1. Barcelona fans were banned from travelling to the Spanish capital for the game, while stones and coins were thrown at the Blaugrana players throughout the game.
Such matches, along with Catalonia's independence struggle and extremely radical fan bases, formed the foundation of an unending rivalry that has long surpassed the casual dislike between other footballing clubs.
El Clasico has seen all-out brawls breaking out on the pitch between the opposing sides, and refereeing decisions that could make you swear the officials were bought. Each derby comes with an incident with a potential capacity to disrupt the entire game, and while players and coaches are now very likely to be fined for any misdemeanours, it doesn't always stop the players and their fans from getting riled up easily.
With the next El Clasico only hours away, let's take a look at the five most controversial moments of the last two decades.
Honourable mention: Barca fans throw a pig's head at Luis Figo
Luis Figo, who had played for Barcelona, made a £37 million move to their nemesis club Real Madrid in the summer of 2000. During a derby at the Nou Camp later that year, the Blaugrana faithful came prepared to bombard the former Barca man with a good number of items that included whiskey bottles, golf balls, cigarette lighters, and infamously - a pig's head.
#5 Zinedine Zidane squares with Luis Enrique
Zinedine Zidane and Luis Enrique had their first match-up as managers of the El Clasico sides in 2016.
The duo once had a well-publicised clash in 2003 that saw the current Real Madrid manager receive a yellow card. Zidane had caught former Barca defender Carles Puyol with a flailing arm, and Enrique was the first player to confront the Madrid man. Zidane, perhaps already incensed, did not waste any time with words, but instead, proceeded to push Enrique in the face.
Barca fans were, to put it mildly, provoked when Zidane received only a yellow card for his actions. Enrique has since come out to state that he has no bad memories from that day.
#4 Pepe stamps on Lionel Messi
In 2012, during the Copa del Rey quarter-final first leg, it was just another day at the office for Lionel Messi. The Argentine was intent on wreaking havoc on Real Madrid's defence right in the Santiago Bernabeu.
Perhaps letting his frustration get to him, Pepe decided to slow Messi down by deliberately stamping on his hand. Messi had been lying on the ground, and Pepe used that opportunity to take out his frustrations on Messi. Lucky for him, the referee did not see the incident, but the visiting fans, as well as Barca players, were understandably upset.
Later, Pepe would apologise for the incident, which he termed unintentional.