Chelsea have appointed former Porto boss Andre Villas-Boas as their new manager on a three-year deal.
The 33-year-old resigned from his position as manager of Porto on Tuesday and will join the Stamford Bridge club with immediate effect.
Villas-Boas won the domestic treble and became the youngster boss to win the Europa League with the Portuguese side in his first season as manager at the Estádio do Dragão.
A Chelsea statement said: "He is one of the most talented young managers in football today and has already achieved much in a relatively short space of time.
"His ambition, drive and determination matches that of Chelsea and we are confident Andre's leadership of the team will result in greater successes in major domestic and European competitions.
"Andre will bring his coaching experience back to a club he is already very familiar with, having previously worked here for three years.
"He has always been highly regarded at Chelsea and everyone here looks forward to welcoming him back and working with him."
Porto earlier confirmed that Chelsea had paid the £13.3 release clause on Villas-Boas' contract, allowing them to talk to the Portuguese manger.