The January transfer window can be a quiet one, with most clubs usually not wanting to tinker with their squads too much midway through the season.

But that's not always the case. Sometimes, a side will sense an opportunity to bring in a high-class player, and will be more than happy to splash the cash to get their man.

Which brings us on to the question: who are the most expensive January signings in history?

Thanks to Transfermarkt, we have the answer. Here's the top 10...

10. Ferran Torres: Man City to Barcelona - €55m (£49.5m)

This deal has only just gone through, but it sees Torres enter the top 10 straight away. Only a matter of months ago, Barcelona could not afford to keep Lionel Messi, but they have somehow found enough money to add Torres to their squad.

The 21-year-old has had an injury-hit campaign at Man City, but has shown glimpses of his talent for Pep Guardiola's men since arriving in the Premier League in August 2020, and his eye-catching international record of 12 goals in 22 caps suggests that he has a big future ahead of him.

9. Fernando Torres: Liverpool to Chelsea - €58.5m (£52.7m)

From one Torres to another. When Chelsea signed the World Cup winner in 2011, there was little reason to think that he wouldn't be a success.

However, things never really worked out for the Spaniard during his time at Stamford Bridge as he struggled to establish himself as the team's main man up top. Still, he did score *that* goal against Barcelona in the Champions League semi-final. Perhaps that moment alone justified his hefty transfer fee.

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8. Oscar: Chelsea to Shanghai Port - €60m (£54m)

Oscar spent five years at Chelsea, winning the Premier League twice with the Blues. However, in 2017, Shanghai Port came calling with an offer that he couldn't refuse. 

He won the Chinese championship in his first year at the club, and the Super Cup in the following season. He remains on their books for now.

7. Diego Costa: Chelsea to Atletico Madrid - €60m (£54m)

Diego Costa in action for Atletico Madrid

There was a period where Costa was close to unplayable. The centre forward powered Atletico to a shock league title win in 2014, and then led the line for Chelsea when they triumphed in the Premier League in 2015.

His time at Chelsea did not end particularly well as he fell out with Antonio Conte, but Atletico clearly felt that he still had something to offer and spent in excess of £50m on him in 2018. His second spell at the club was not as impressive, and he was released at the start of 2021.

6. Bruno Fernandes: Sporting Lisbon to Man United - €63m (£56.7m)

Fernandes has made a serious impact at Old Trafford since he moved to United just under two years ago. He registered eight goals and seven assists in the Premier League in his first half-season, and followed that up by scoring 18 goals and providing 13 assists in his maiden full campaign.

He has not been at his best in recent months, with the side struggling to build momentum, but it is surely only a matter of time before he starts firing in the goals once more.

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5. Pierre-Emerick Aubameyang: Borussia Dortmund to Arsenal - €63.8m (£57.4m)

Pierre-Emerick Aubameyang has had a largely successful spell at Arsenal

Aubameyang was signed by Arsene Wenger in 2018, and much of his first three years at the Emirates was a roaring success.

During that period, he won the Premier League Golden Boot and the FA Cup, scoring twice in the final. However, his relationship with Mikel Arteta has since become strained, and his future at Arsenal is now far from certain.

4. Christian Pulisic: Borussia Dortmund to Chelsea - €64m (£57.6m)

Pulisic was actually immediately sent back on loan to Dortmund for the rest of the season in 2019, but this deal was signed off in January of that year.

In truth, his Chelsea career has been a little underwhelming thus far, largely due to injuries and the fierce competition for places at the club. He is still only 23, though, so there is plenty of time for him to prove his worth moving forward.

3. Aymeric Laporte: Athletic Bilbao to Man City - €65m (£58.5m)

City's team looked close to perfection before Laporte arrived, but Guardiola wanted a player to bolster his backline. The Spanish international has proven to be a fine addition at the Etihad.

He has played his part in City winning the Premier League in three of the last four seasons, and has formed a formidable partnership with Ruben Dias this term.

2. Virgil van Dijk: Southampton to Liverpool - €84.7m (£76.2m)

There were a few eyebrows raised when Liverpool spent over £75m on van Dijk in January 2018. It was a gamble that has certainly paid off.

The 30-year-old has played a vital part in the Reds' success over the last four years, which has included winning the Champions League and Premier League. Jurgen Klopp's side missed him badly when he suffered a serious knee injury last season.

1. Philippe Coutinho: Liverpool to Barcelona - €135m (£121.5m)

Coutinho takes top spot, and by some distance. In the same month that van Dijk arrived at Anfield, Coutinho departed and it has not gone well for the playmaker.

Due to a combination of injuries and loss of form, he has never managed to live up to expectations. His days at Barcelona appear numbered, but he does not turn 30 until June, so he may fancy his chances of reviving his career elsewhere in 2022. 

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