Chelsea have confirmed the transfer of Kalidou Koulibaly from Napoli. The experienced centre-back will be part of manager Thomas Tuchel's rebuilt defence after the summer departures of Antonio Rudiger and Andreas Christensen.
Koulibaly, 31, played for Napoli since 2014 and made 26 Champions League appearances, making him an ideal fit for a Blues side which will be aiming for a deep run in the competition next season.
Chelsea may consider further reinforcing their back-line before the end of the summer, with Paris Saint-Germain star Presnel Kimpembe and Matthijs de Ligt having been heavily linked over the past month.
How much will Chelsea pay for Koulibaly?
Chelsea will pay £34 million ($41m), including add-ons, to complete the deal for the experienced Napoli defender.
What is Koulibaly's salary and contract length?
The Senegal international, who captained his country to Africa Cup of Nations glory back in February, has signed a four-year contract in west London through to the summer of 2026.
He will earn an annual salary of around £8.5m ($10m) during his time at Stamford Bridge.
Why did Koulibaly choose Chelsea?
A big-money addition to Tuchel's ranks has told the Blues' official website on choosing to head for west London: "I’m very happy to be here with this team at Chelsea. It’s a big team in the world and my dream was always to play in the Premier League.
"Chelsea came first to get me in 2016 but we didn’t make it. Now when they came to me I accepted it because they really wanted me to come to the Premier League to play for them.
"When I spoke to my good friends Edou and Jorginho they made my choice easier so I’m really happy to be with you today.
"I want to thank the fans because I saw a lot of them in London and on the plane everybody was happy for me to be here. So I want to thank them and I hope the season will be really good and we will give some good moments to the fans."
Why are Chelsea signing Koulibaly?
After losing starting centre-back Rudiger on a free transfer to Real Madrid earlier this summer, and Denmark star Christensen on a free transfer to Barcelona, it was imperative that Chelsea made a move for at least one renowned defender during the transfer window.
Thiago Silva, another regular in Tuchel's defence, will turn 38 in September and is presumably near the end of his European career.
Koulibaly should bring assurance to the back-line and help the team remain competitors for major honours despite high-profile departures.
He has been regarded as one of the outstanding centre-backs in Europe for a number of years now, and was also a transfer target for Juventus and Barcelona this summer.
Who else will Chelsea sign this summer?
Chelsea have already confirmed the £47.5 million ($57m) signing of winger Raheem Sterling after missing out on Leeds winger Raphinha.
They may now look to add another centre-back, with there being an interest in adding Kimpembe, while Sevilla's Jules Kounde has also been linked.
Matthijs de Ligt is another who has been on the Blues' radar although a switch to Bayern Munich looks more likely for the Juventus defender, while Nathan Ake appears likely to remain with Manchester City.
It would appear that Cristiano Ronaldo is another who will not be moving to the west London club, with Tuchel reportedly having decided against pursuing the want-away Manchester United forward.