Chelsea have signed French centre-back Wesley Fofana from Leicester City on a seven-year deal for a fee in the region of £70m.
France Under-21 international Fofana has made 37 Premier League appearance since joining Leicester from French side Saint-Etienne in 2020.
"The two last days have been really big for me and I'm very happy," he said.
"I trained this morning with the team and it's a dream for me. I'm very excited to start playing games for the fans and the club.
"I'm here to win trophies - the Champions League, Premier League, FA Cup, Carabao Cup, everything. I came here to win and the club is built to win trophies so I'm here to continue that."
He is the third most expensive Premier League defender behind Manchester United's £80m purchase of Harry Maguire in 2019 - also from Leicester - and Liverpool's Virgil van Dijk, who joined the Reds for £75m in 2017.
Chelsea chairman Todd Boehly - who has spent almost £250m in his first transfer window since buying the club from Roman Abramovich - said: "Wesley is a hugely promising defender who has already proven his quality in the Premier League at a young age.
"We are delighted we were able to bring one of Europe's most exciting talents to Chelsea and further strengthen that area of our squad, both for this season and many more to come."
