Real Madrid have announced they have completed the signing of Brazilian star Kaka from AC Milan on a six-year deal.
A press conference with the 27-year-old, who had been linked with Chelsea, is planned for 0100 BST on Tuesday.
The fee is reported to be £56m, which would be a new world record in pounds, surpassing the £45.6m Madrid paid for Zinedine Zidane in 2001.
"It will be very difficult to fill the void that will be left by Kaka," said an AC Milan statement.
"[He is] a shining example of professionalism and commitment.
"AC Milan thanked the man and the great champion Kaka for his decisive contribution to the many victories achieved in the six years of his commitment."
Perez clearly hasn't learned from his first spell as President
The Brazilian Football Confederation (CBF) earlier said he had a medical in Recife, where Brazil face Paraguay in a World Cup qualifier on Wednesday.
A short statement on the Real site said: "He is a Real Madrid player now after an agreement was reached with AC Milan.
"The Brazilian has passed all the tests of the medical examination satisfactorily. Kaka has signed a contract with Real Madrid for the next six seasons."
The official unveiling in Madrid is unlikely to take place until the end of the month, as Kaka is in the Brazil squad for the Confederations Cup in South Africa.
Kaka is the first capture for the returning Real president Florentino Perez, who previously led the Spanish club from 2000 to 2006 - during the famous Galacticos era.
That resulted in the spending of large fees to bring the likes of Ronaldo (£23.2m), David Beckham (£24.5m), Luis Figo (£37m) and Zidane to the club.
Zidane joined Real from Juventus for a fee reported to be 73m euros in 2001.
Kaka's fee is thought to be around 65m euros, but with the fluctuation in exchange rates his fee represents the most ever paid in British terms.
Perez's comeback is on the back of a pledge to relaunch another Galacticos era, with Kaka one of his chief targets.
The Brazilian joined Milan from Sao Paolo in 2003 for just 8.5m euros and has since enjoyed great success.
In 2007 alone Milan picked up the Champions League as well as the Uefa Super Cup and the Fifa Club World Cup, whilst his Brazil side won the Confederations Cup and he was also voted the Fifa World Player Of The Year.
Archive - Kaka scores against Croatia
He has also won the Seria A title, and was part of Brazil's 2002 World Cup-winning squad.
Although under contract at the San Siro until 2013, in January Manchester City made an audacious £100m bid, offering a reported £500,000 a week in wages but Kaka opted to stay in Italy.
More recently he was linked with a move to Stamford Bridge, following the arrival of former Milan boss Carlo Ancelotti at Stamford Bridge.