Cristiano Ronaldo is determined to write another chapter in his illustrious career after joining Juventus in a 112-million-euro ($A177 million) deal from Real Madrid.
The Portugal forward, 33, agreed a four-year contract with the Serie A champions in one of the most dramatic moves in European football, which was confirmed on Tuesday.
Ronaldo scored a record 451 goals over nine years at the Bernabeu, having signed from Manchester United and helping deliver four Champions League triumphs.
However, as the Spanish giants prepare for life under new head coach Julen Lopetegui, Ronaldo felt the time was right to move on.
In an open letter posted on Real Madrid's website, Ronaldo pleaded with fans to understand his decision.
"These years at Real Madrid and in this city of Madrid have been possibly the happiest of my life," he said.
"I only have feelings of enormous gratitude for this club, for these fans and for this city. I can only thank all of them for the love and affection I have received.
"However, I believe that the time has come to open a new stage in my life and that is why I have asked the club to accept transferring me.
"I feel that way and I ask everyone, and especially our followers, to please understand me."
Juventus revealed in a club statement that they would pay 100 million euros ($A 158 million) to Madrid over two financial years and "additional costs" of 12 million euros ($A 19 million).
Real expressed their gratitude to a player who helped the club to four Champions League successes, three FIFA Club World Cups, two La Liga titles and two Copa del Rey crowns.
A club statement said: "Real Madrid CF communicates that, in response to the will and request expressed by the player Cristiano Ronaldo, it has agreed to transfer him to Juventus FC.
"Real Madrid wants to express its gratitude to a player who has proved to be the best in the world and who has marked one of the brightest times in the history of our club and world football.
"Beyond the conquered titles, the trophies achieved and the triumphs achieved on the playing fields during these nine years, Cristiano Ronaldo has been an example of dedication, work, responsibility, talent and improvement."