Brazil's 2007 world footballer of the year Kaka's completed his transfer from Serie A side AC Milan to Real Madrid.
The 27-year-old's signed a six-year contract with the Spanish giants for a reported fee of $145 million.
That would make it the second biggest ever transfer - after that of French player Zinedine Zidane, who cost Real Madrid $167 million eight years ago.
Kaka has been at AC Milan since 2003, and been the subject of a massive transfer offer from English Premier League side Manchester City in January but the deal eventually came to nothing.
