The transfer of Cristiano Ronaldo from Real Madrid to Juventus in 2018 sent shockwaves through world football and it appeared to happen quite suddenly.
Indeed, given that Ronaldo himself had just the year before indicated he wanted to finish his career at the Santiago Bernabeu, it was something of a surprise to many casual observers.
The Portugal captain had become the bedrock of Madrid's dominance in the Champions League, inspiring them to four titles, and he wrote his name into the history books as the club's record scorer with 450 goals.
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So, considering everything was going so well on the pitch, what was it that led Ronaldo to leave La Liga for Serie A and the hills of Turin?
Why did Cristiano Ronaldo leave Real Madrid for Juventus?
Ronaldo claims that he left Real Madrid for Juventus because he felt he was "no longer indispensable" in the eyes of Blancos president Florentino Perez.
He added that Juventus demonstrated a desire to have him on their team which he felt was much stronger than that of Real, while noting that Zinedine Zidane's departure also played a part.
"I felt within the club, especially from the president, that I was no longer considered in the same way as I was at the beginning," Ronaldo said in a 2018 interview with France Football.
"For the first four or five years, I felt like Cristiano Ronaldo. Less so after.
"The president looked at me in a way that suggested I was no longer indispensable if you know what I mean. That is what made me think about leaving."
Ronaldo's stated reasons for leaving the Spanish capital may not necessarily tell the whole story, of course.
Towards the end of his time at the club, reports began to suggest that Ronaldo wanted a pay rise following Madrid's 2018 Champions League triumph.
The prospect of Neymar's arrival - ostensibly as a replacement - was also said to have played a part in the former Manchester United star's decision, according to former Real president Ramon Calderon.
The ex-Blancos chief told Radio Villa Trinidad: “Cristiano asked for a raise after winning the Champions League and Florentino denied it. Cristiano also got angry because he heard that Madrid would be willing to pay a lot of money for Neymar.
“Florentino told him that if he brought in a cheque for 100 million euros he would let him go and that's how it was.”
Ronaldo has, however, denied that the move came about as a result of a dispute over remuneration, saying: "If it had all been about money, I’d have moved to China, where I would have earned five times as much than here [at Juventus] or at Real. I did not come to Juve for the money. I earned the same in Madrid, if not more."
Did Cristiano Ronaldo leave Real Madrid over tax case?
Another hypothesis that has been put forward as an explanation for Ronaldo's switch to Juventus is the fact that he was the focus of a high-profile tax court case in Spain.
The case was brought to a conclusion at the beginning of 2019, with Ronaldo paying in the region of €19 million in fines.
When the prosecution against him began back in 2017, reports in Spain suggested that the Portuguese had threatened to leave the country over his treatment and it was clear that the issue troubled him.
He notably took to social media to slam "fake news" in early 2018, accusing his detractors of trying to "spoil the beautiful moment" he was experiencing in his career, for example.
However, Madrid president Perez subsequently dismissed the notion that the case had anything to do with the star's departure from the Spanish capital.
“There were rumours about him wanting to leave because of the tax case, but that’s not the reality of the situation," he told Onda Cero in May 2019.
"He wanted a change and to improve his contract, so he found it at Juventus and everyone was happy.”