10. John Obi Mikel (Lyn Oslo/Man United to Chelsea, 2006)

Fee: £16m

Even now, nobody seems quite certain as to what happened between Manchester United, Chelsea and Norwegian side Lyn. In 2005, United claimed an agreement had been reached with player and club, and even released pictures of him holding their shirt.

Chelsea were furious, insisting that they had a prior agreement to sign Mikel, evidenced by the financial assistance they'd given during his education in Norway. To further complicate matters, it would later transpire that the Nigerian's original registration with Lyn had allegedly been forged by a club director.

It remains a rabbit hole of a transfer involving opaque agenting practices, misinformation, and – seemingly – a healthy dose of fraud. Whatever the truth, the Norwegian Football Federation's intervention led to Chelsea paying a split fee of £16m to Manchester United (£12m) and Lyn (£4m) for a player who would win every domestic and continental trophy available to him over the next decade. SSB

9. Carlos Tevez and Javier Mascherano (Corinthians to West Ham, 2006)

Fee: Undisclosed

The most entertaining aspect of this deal is unquestionably that, with West Ham in deep relegation trouble, Alan Pardew generally opted to play Marlon Harewood and Hayden Mullins instead of Carlos Tevez and Javier Mascherano.

Arriving in August 2006, both players had left Upton Park by the summer of 2007: Mascherano after an initial January loan to Liverpool, Tevez following a blistering New Year resurgence that would keep West Ham – by then managed by Alan Curbishley – in the division.

The controversy bubbles to this day: both players' rights were owned by Media Sports Investments (MSI) rather than Corinthians, and West Ham were not only fined by the Premier League for breaching the rules governing registration but also forced to arrive at a settlement with relegated Sheffield United, who – according to Neil Warnock – went down as a direct consequence of Tevez's form. Crucially, the Hammers were allowed to keep their place in the division, though, and the demoted United have yet to even threaten a return.

If third-party ownership had been a vague, frowned-upon practice before, it has since become spectacularly illegal: in June 2008, the Premier League approved rules L34 and L35 to prevent any future recurrence. Thou shalt not part-own players. SSB

8. Eric Cantona (Leeds to Man United, 1992)

Fee: £1.2m

Legend has it that it was a spur-of-the-moment thought. Alex Ferguson, who happened to be in the room when his bosses at United got a phone call from Leeds to inquire about the availability of Denis Irwin, thought it might be worth asking the same about Eric Cantona. The Frenchman, whose fiery temperament worried the Leeds hierarchy, needed little persuasion to switch, the laughable fee of £1.2m arguably representing football’s most glorious bargain.

In just half a decade at United, Cantona made a strong case for being the club’s greatest-ever player, his grit, flair and charisma doing much to forge the aura on which the Ferguson era was founded, and his unrelenting dedication to training proving instructive to a certain group of up-and-comers.

His form at the tail end of the 1995/96 season remains one of the most remarkable sustained individual feats of the modern age. That he retired without warning aged just 31 has only added to his legend. AH

7. Luther Blissett (Watford to Milan, 1983)

Fee: £1m

“I was stunned that someone was prepared to pay that much for a footballer,” Blissett would later tell FFT of his move to Italy the year after he top-scored the First Division with 27 goals for plucky Watford.

Just one season later, though, Blissett was back at Vicarage Road for half the cost after a season of struggle at San Siro. It’s worth remembering, though, that this was an altogether different Milan team that had only just returned to Serie A after a stint in the second tier, and Blissett struggled with a new style in foreign climes.

Subsequently, he mustered only five goals in his 30 Serie A games and was happy for a return home. “It was hugely frustrating. I had no real passion for winning matches with dull, defensive football,” Blissett admitted. “The move really re-enforced that the Italians truly are the masters of defence. I would love to have gone back four years later when their game had evolved into a more attacking one.” JB

6. Jean-Marc Bosman (RFC Liège to Unattached, 1990)

A landmark moment in modern football owes everything to an otherwise inconsequential player. Jean-Marc Bosman was playing for RFC Liège when he decided to take his employers to court over his employment rights in the summer of 1990. Dunkerque had wanted to sign him but wouldn’t meet Liège’s asking price, resulting in his club slashing his wages by a whopping 75%.

Five years and one arduous court case later, Bosman was ruled free to move at the end of his contract without money needing to change hands between parties. The age of player power had dawned.

The Bosman Ruling – a term that quickly became a staple of the footballing lexicon – meant that any player allowing their contracts to run down was implicitly threatening their club, and were often hurriedly offered a fat new contract to deter a move.

Depending on your point of view, it either turned football into a zero-loyalty game populated by self-interested brats, or one of the few industries where real power lies in the hands of the labourer. Take your pick. AH

5. Kevin Keegan (Hamburg to Southampton, 1980)

Fee: £420,000

Time and management may have diminished the magnitude of Kevin Keegan as a player. By 1980 he was a Ballon d’Or-winning England captain, pop star, TV regular, brand ambassador, This Is Your Life subject, and one of very few Englishmen playing abroad.

If he were to return, it would surely be to a huge team… but Liverpool didn’t want to activate their buyback clause and Lawrie McMenemy stunned football by wrangling him to unfashionable Southampton for £420,000.

Bagging 37 in 68 games, Keegan led a flamboyant Dad’s Army of ageing stars who topped the league by January 1982, but fell away. That summer Keggy would take his goals to Newcastle. GP

4. Roberto Baggio (Fiorentina to Juventus, 1990)

Fee: £8m

"If you can’t beat ‘em, join ‘em" goes the old adage, and Roberto Baggio would do just that after failing to help Fiorentina beat Juventus in the 1990 UEFA Cup Final.

The Viola had spent two years helping him overcome a serious knee injury, only for Baggio to join their bitter rivals just weeks after they had beaten them to yet another trophy.

Tension between the two clubs had always been high, but not even a world record sum of £8 million could appease Tuscan supporters, who spent the days following the announcement rioting in the renaissance city.

Baggio went on to Scudetto and Ballon d’Or glory with Juventus, but never gave the Old Lady his full affection, refusing to take a penalty and pulling on a Fiorentina scarf when he was substituted during his first game back at the Stadio Artemio Franchi. AD

3. Mo Johnston (Nantes to Rangers, 1989)

Fee: £1.9m

Strictly speaking, ‘MoJo’ wasn't the first Catholic to sign for Rangers, but when the diehard Celtic fan – who'd also become a goalscoring hero at Parkhead in the mid-’80s – put pen to paper for Graeme Souness's side in July 1989, all hell broke out in sectarian Glasgow.

Loyal Protestants vowed never to return to Ibrox, and staunch Catholics burnt effigies of Mo for promising to re-sign for them (from Nantes) before spurning his old club at the 11th hour for their deadly rivals.

Slowly, the fuss and furore died down, and Mo did what he did best – scored goals for his new club, who won the title in his only two seasons there before a £1.5m move to Everton in 1991. JS

2. Sol Campbell (Tottenham to Arsenal, 2001)

Fee: Free

In 2001, upon the expiration of his Tottenham contract, the club's then-captain became the first player since Pat Jennings to move from White Hart Lane to Highbury.

To hear Sol Campbell tell this story is strange indeed. He wanted to win trophies, he didn't feel Tottenham were able to match his ambition, but believed that Arsenal ultimately would. Simple – and yet to this day he seems baffled by the fuss it caused. Note, in particular, the surprise he expresses in interviews at the hostility he would often face during north London derbies.

He should never have been subjected to any chanting with racial or homophobic tones – that is inarguably true and a stain that the Spurs' fanbase has to wear – but his blanket rejection of criticism has always been a contrary response to one of the most treacherous actions witnessed in modern football. SSB

1. Luis Figo (Barcelona to Real Madrid, 2000)

Fee: £36.2m

“As a player at Barcelona, he never hid from anything,” commented one of Figo’s team-mates after his massively controversial £36.2 million move to rivals Real Madrid in 2000.

Brave or not, even the Ballon d’Or winner was shocked at the level of vitriol directed at him when he returned to the Camp Nou with his new club in October 2001 – whenever he touched the ball, a hail of oranges, cigarette lighters and bottles (the pig’s head was thrown a year later) rained onto the pitch.

Wisely, he avoided taking corners that day, instead spending his time admiring the “Judas” and “Scum” banners dotted around the stadium in his honour.

Figo’s arrival ushered in a new era of Galacticos at Real Madrid; Zinedine Zidane, Ronaldo and David Beckham all followed in the next three seasons to help make up football’s most iconic array of stars. JS

55-41 • 40-31 • 30-21 • 20-11 • 10-1

New features every day on FourFourTwo.com