Chelsea have completed the signing of French midfielder Tiemoue Bakayoko from AS Monaco on a five-year deal believed to be in the region of £40m.
Chelsea made the announcement on their official website on Saturday.
"Tiemoue Bakayoko is a Chelsea player having today completed a transfer from Monaco," a statement on Chelsea's website reads.
"Bakayoko, 22, is a tall, strong and quick central midfielder who was instrumental in Monaco’s Ligue 1 triumph last season, as well as their impressive run to the Champions League semi-finals.
"He recently made his debut for France in the same line-up as new team-mate N’Golo Kante, and is widely recognised as one of the best young central midfielders in European football."
Bakayoko, who will wear the No.14 shirt, said: " I am very happy to be here and to join this great team. 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 becomes Chelsea's third signing after Willy Caballero and Antonio Rudiger arrived from Manchester City and Roma respectively.