Maurizio Sarri has left Chelsea to become manager of Serie A champions Juventus on a three-year deal.
Sarri, who joined the Blues from Napoli in July 2018, led them to third in the Premier League and won the Europa League in his one season in charge.
It is understood compensation in excess of £5m has been agreed between the two clubs for the 60-year-old.
Sarri will replace fellow Italian Massimiliano Allegri, who left Juventus at the end of last season.
“In talks we had following the Europa League final, Maurizio made it clear how strongly he desired to return to his native country, explaining that his reasons for wanting to return to work in Italy were significant,” said Chelsea director Marina Granovskaia.
“He also believed it important to be nearer his family, and for the well-being of his elderly parents he felt he needed to live closer to them at this point.”
Sarri signed a three-year deal last July but now becomes the ninth full-time manager to leave Chelsea under Roman Abramovich, who bought the club in 2003.
Derby boss and former Chelsea midfielder Frank Lampard has been linked with taking over from Sarri but the Blues are yet to make contact with the Rams.
The Championship club are keen to extend Lampard’s deal – which has two years left – and have opened talks with the 40-year-old.
Chelsea are unable to sign any players after being given a two-window transfer ban by world governing body Fifa – a decision they are appealing against at the Court of Arbitration for Sport.