Chelsea have made their first major signing ahead of the new season, signing Roma defender Antonio Rudiger in a €35million deal.
Rudiger is fresh off helping Germany to the Confederations Cup title and has penned a five-year contract at Stamford Bridge. The Blues could pay an extra €4m in bonuses.
With John Terry released and Nathan Ake having joined Bournemouth for £20m, Rudiger's arrival follows the signing of Willy Caballero as back-up to goalkeeper Thibaut Courtois.
The defender told the club's official website: "It's a great feeling because not every player has the opportunity to join a huge club like this.
"I am looking forward to meeting up with my new team-mates and I'm very proud to officially become a Chelsea player."
The arrival of Rudiger may sate boss Antonio Conte, who has reportedly grown frustrated with the club's lack of action in the early stages of the window.
The Premier League champions have missed out on the signing of Everton striker Romelu Lukaku, who has opted for a £75m move to Manchester United, rather than return to London.
Conte's title charge last season was built on a solid back three of Cesar Azpilicueta, David Luiz and Gary Cahill, although the Blues did not generally look as solid when that trio was broken up, with Terry struggling to convince Conte of his enduring abilities, while Kurt Zouma spent last season recovering from a serious knee injury.
Rudiger's signing brings depth and talent to the Blues, and he has experience of playing in a three-man defence at Roma.
The 17-cap defender made 56 league appearances in two seasons for the Giallorossi, helping Roma qualify for the Champions League by finishing second in Serie A last season.
Tiemoue Bakayoko and Alex Sandro are thought to be high on Conte's wishlist as he prepares for a Premier League title defence and Chelsea's return to Champions League action next season.
