Middlesbrough are no strangers to splashing the cash.

While other clubs have received hefty investment from other countries around the world the Teessiders are one of the few clubs who remain owned by a local businessman in the shape of Steve Gibson.

That's why he's regarded as one of best, most loyal chairmen in the English game.

Gibson has made some extraordinary signings during the last 30 years with plenty of them costing a substantial sum, but in addition to the top arrivals there have been some players who really struggled to live up to the price tag.

Of course with the club now plying their trade outside of the Premier League it makes things a little bit tougher to spend big sums on players, but what we do know is that Gibson will always back the club if the right deal comes along.

But who are the club's record signings, and where are they now? We take a look at the most expensive players ever to join the Teessiders.

Middlesbrough's signing of Jonathan Woodgate was a significant piece of business for the club.

After spending a season on loan at the Riverside Stadium, the Teessiders completed a £7million deal with Real Madrid to bring the central defender back to the club on a permanent basis.

Unfortunately that permanent stay didn't last long with Woodgate joining Tottenham Hotspur in January the following year.

Spells with Spurs and Stoke City followed before the defender rejoined Middlesbrough again as a player before retiring from the game.

Since then Woodgate has managed Middlesbrough and is currently the interim head coach for Bournemouth as they seek promotion to the Premier League.

What a signing this was for Middlesbrough.

Bryan Robson brought in some big name players such as Nick Barmby, Juninho, and Emerson, but it was the addition of the Italian that really captured the world's attention.

Ravenelli had just won the Champions League with Juventus when a £7million move to Middlesbrough was agreed.

In his season with the club he scored plenty of goals but couldn't stop the Teessiders from suffering relegation, at which point he moved on to join Marseille.

He then played for clubs such as Lazio and Derby County before retiring as the game and working as a manager and a pundit.

The striker was often a thorn in the paw of Steve McClaren's Middlesbrough side during the noughties, so what better way to solve the problem than by signing him?

Yakubu left Portsmouth and joined Middlesbrough in the summer of 2005 for a fee of £7.5m in a campaign that would prove to be memorable as the club went on to secure a place in the UEFA Cup final.

The Nigerian striker enjoyed two strong season at the Riverside Stadium before leaving to join Everton in 2007.

Yakubu spent time in England, China, Qatar and Turkey before his career came to an end in 2017 after a spell with Coventry City.

Since then it's unknown what the striker has been doing with his time.

The central defender spent many successful years with Aston Villa before completing a move to Middlesbrough in 2000.

That fee of £8million proved to be decent value with the defender spending seven years at the Riverside Stadium during a time that saw the club secure their best-ever Premier League finish, win their first-ever piece of silverware while also reaching the UEFA Cup final during the second of two campaigns in Europe.

Ehiogu spent time with Rangers and Sheffield United before hanging up his boots in 2009.

He went on to enjoy a coaching career with the England youth set-up and the Tottenham Hotspur development squad before sadly passing away in April 2017.

The Italian joined Middlesbrough for £8.15m as their flagship signing in the summer of 2002 after proving himself as one of Italy's hottest prospects.

A decent couple of seasons were had the Riverside Stadium before the striker was sent out on loan for the 2004-05 season in which he returned to his homeland for the duration of the season.

But with a point to prove Maccarone returned to Middlesbrough for the 2005-06 in which he established himself as a local hero after scoring the crucial goals in back-to-back UEFA Cup comebacks against FC Basel and Steaua Bucharest in the quarter-finals and semi-finals respectively.

Maccarone spent most of the rest of his career in Italy before retiring from the game in 2020.

It's now thought that the striker is looking to start a career as a coach and is undergoing his coaching qualifications.

The striker moved to Middlesbrough in February 2016 for a fee of £9million after taking the decision to leave Blackburn Rovers.

Rhodes played a crucial role in helping the Teessiders to secure promotion to the Premier League that season but soon found himself out of favour after the club completed a deal to sign Alvaro Negredo.

A loan spell with Sheffield Wednesday was made permanent in 2017 and that's where the frontman has been contracted ever since.

The Owls are enduring a torrid season this term, and while Rhodes has hit some decent form of late it seems like there will be a big battle if they're to avoid the drop.

With a contract that expires this summer the frontman could be set for pastures new come the new season.

A player signed as part of Middlesbrough's plan to bounce straight back after relegation.

Braithwaite joined for £9million in the summer of 2017 after leaving Toulouse but divided opinion during his time at the Riverside Stadium.

Despite his undoubted quality, the forward refused to commit his future to the club and ended up leaving the club on loan on two occasions as he failed to embrace the challenge of the Championship.

But after finally leaving the club in favour of a move to Leganes, the striker was afforded the chance of a lifetime after completing a shock move to Barcelona.

Braithwaite is still at the Nou Camp and is thought to be living the dream as he continues to play for one of the top clubs in world football.

A player who spent just one year at the Riverside but is regarded as something of a fans' favourite.

De Roon joined the club for £11.75million after leaving Atalanta in July 2017 and was a first team regular during Middlesbrough's season in the Premier League.

The Dutch midfielder was a box-to-box player who scored some memorable goals during his season, including a last-gasp equaliser against Manchester City.

However after suffering relegation De Roon left the club and rejoined his old team in Serie A.

Still with Atalanta, De Roon is a first team regular and has helped the club to compete in the Champions League while also proving himself as a key player for the Netherlands national team.

Number two in the list is probably regarded by many supporters as one of the worst signings in their history.

After scoring goals for fun with Heerenveen in the Dutch Eredivisie, Middlesbrough broke the bank as they brought the Brazilian to the Riverside Stadium for a fee of £12.8million in January 2008.

Despite a couple of excellent displays against Manchester United and Tottenham Hotspur, Alves really struggled to recreate his former glory during his time with Middlesbrough - much to the frustration of the supporters.

After just one full season with the club Alves was shipped out to Qatar where he stayed until 2015.

It was then that he retired from the game with his time at the Riverside Stadium clearly being the turning point in what looked like a promising career.

Middlesbrough's most expensive ever signing is still at the club, but perhaps not for long.

Assombalonga moved to Middlesbrough for £15million in the summer of 2017 as part of the club's plan to bounce back to the Premier League but unfortunately struggled to score the required goals to do that.

The Teessiders reached the play-offs in 2018, before falling short in 2019 while in 2020 the club were actually closer to being relegated again.

This term has been an improvement for the club but Assombalonga has struggled to find his feet and with a contract that's due to expire in the summer it seems increasingly likely that the club-record signing could be about to leave the club for nothing.