Chelsea have completed the signing of defensive midfielder Tiemoue Bakayoko from Monaco for a reported £40 million.
The 22-year-old, who has signed a five-year deal, is expected to line up alongside fellow France international N’Golo Kante next season.
Bakayoko is Chelsea’s third signing of the summer, joining goalkeeper Willy Caballero and defender Antonio Rudiger at Stamford Bridge.
"I am very happy to be here and to join this great team," he told the club’s official website.
"I have grown up watching Chelsea. Signing was the natural thing for me because it is a club I loved very much in my childhood.
"I am now looking forward to evolving under this fantastic coach and alongside so many great team-mates."
Bakayoko arrived at Monaco from Rennes in 2014, making nearly 100 appearances and helping them win the Ligue 1 title last season.
He played a crucial role in Leonardo Jardim side’s run to the Champions League semi-finals last season, including the winning goal to knock out Manchester Cityin the last eight.
So impressive were his performances, France boss Didier Deschamps rewarded him with his international debut against Spain in March
His arrival casts doubt on Nemanja Matic’s future in west London, with the Serb heavily linked with a reunion with former Blues boss Jose Mourinho at Manchester United.