DNA takes a look at the biggest transfers in world football.

Cristiano Ronaldo (£80 million)

Manchester United to Real Madrid

On June 11, 2009, Manchester United accepted an unconditional offer of £80 million from Real Madrid for Cristiano Ronaldo after it was revealed that the winger had again expressed his desire to leave the club.

On June 26, 2009, Real Madrid confirmed that Cristiano would join the club on July 1, 2009, after agreeing to terms and signing a six-year contract.  The Portuguese star's contract is worth €11 million per annum and it has a €1 billion buy-out clause.