Premier League champions Chelsea have completed the signing of Tiemoue Bakayoko from Monaco, with the midfielder signing a five-year contract.
In a move reportedly worth £40million, the 22-year-old's switch to Stamford Bridge from the Ligue 1 winners was completed on Saturday and he will now get the opportunity to work under Antonio Conte.
"I am very happy to be here and to join this great team," Bakayoko told his new club's 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's energy was crucial to Monaco's unlikely 2016-17 title triumph which ended Paris Saint-Germain's four-year dominance of the French top flight and his top-level experience was a key factor in Chelsea's pursuit.
"Tiemoue was outstanding as Monaco emerged as one of Europe's best sides last season and we are delighted to welcome him to Chelsea," said technical director Michael Emenalo.
"Despite his young age he already has plenty of experience as a French title-winner and having competed in the latter stages of the Champions League, we believe he will add considerable quality to our squad."
Bakayoko, who arrived at Monaco from Rennes in 2014, also scored the decisive goal that knocked Manchester City out of the Champions League in March, his header sending Monaco through to the quarter-finals on away goals after a 6-6 aggregate draw.
The Paris-born midfielder, who will wear the number 14 shirt, made his first senior international appearance for France in a friendly against Spain in March, his only cap to date.
He is Conte's second signing of the transfer window following the capture of Germany defender Antonio Rudiger from Roma and is set to join France team-mate N'Golo Kante in central midfield. The deal could also clear the way for Nemanja Matic to secure a reunion with Jose Mourinho at Manchester United.
Monaco wished Bakayoko good luck and thanked him for his service.