Chelsea have appointed former Tottenham and Paris St-Germain boss Mauricio Pochettino as their new manager.
The Argentine, 51, begins his new role on 1 July 2023 on a two-year contract, with an option of a further year.
Interim boss Frank Lampard took Chelsea to 12th in the Premier League - their lowest finish for more than 25 years.
"Mauricio is a world-class coach with an outstanding track record. We are all looking forward to having him on board," the club said.
Chelsea say Pochettino was first choice and the only manager who was brought into the club for talks.
He will work with sporting directors Paul Winstanley and Lawrence Stewart.
"Mauricio's experience, standards of excellence, leadership qualities and character will serve Chelsea Football Club well as we move forward," Winstanley and Stewart said in a statement.
"He is a winning coach, who has worked at the highest levels, in multiple leagues and languages. His ethos, tactical approach and commitment to development all made him the exceptional candidate."
Pochettino is Chelsea's sixth permanent manager in five years following the sacking of Thomas Tuchel and Graham Potter earlier this season, which led to Lampard taking charge on a temporary basis.
He is also the fourth boss of new owner Todd Boehly's reign after the American took over at Stamford Bridge last July.
Since Boehly took over, Chelsea have spent more than £550m on players with their Premier League record of £288m in January totalling more than all the clubs in the Bundesliga, La Liga, Serie A and Ligue 1 combined.
Incomings like World Cup winner Enzo Fernandez and Ukraine winger Mykhailo Mudryk could not lift a poor Chelsea season however, as the Blues lost to Real Madrid in the quarter-finals of the Champions League.
They also suffered third-round exits in both the FA Cup and Carabao Cup.
Pochettino had been linked with a return to Tottenham after they parted company with Antonio Conte in March, but he has instead joined his former club's London rivals.
Having started his managerial career with Espanyol before a 16-month spell at Southampton, he then managed Spurs from 2014 to 2019.
The Argentine guided his side to the League Cup final in 2015 and a Premier League runners-up spot in 2016-17, with Spurs missing out on winning both to Chelsea, and the 2019 Champions League final.
He also oversaw an infamous London derby in May 2016 in which Spurs picked up nine yellow cards compared with three for the Blues, the result ending their title hopes for the season.
Following his spell at Tottenham, Pochettino took over from Tuchel at PSG in January 2021.
The French club finished second in Ligue 1 at the end of the 2020-21 season but did win the Coupe de France and the Trophee des Champions, which were the first trophies of Pochettino's managerial career.
Guillem Balague, European football expert
Joining Chelsea is not a decision Pochettino has taken lightly; he has turned down a number of potential suitors since leaving Paris St-Germain in July 2022.
But none have ticked as many boxes as Chelsea, and he initially turned down Boehly until he was offered more control.
Much, of course, will depend on who he can bring in, with a need to find a striker clearly a main objective. Should Romelu Lukaku manage to steer clear of injury, he could well be an option, although he is going to have to jettison some players before contemplating adding to the squad.
What his time at PSG taught him is he needs to return to his essence, with all his passion and intensity, not dissimilar to the relationship he enjoyed with his players at Spurs.
For that, he has taken a good look at himself and what he did wrong at the French club, what he could have done better and how he can avoid making similar mistakes at Chelsea.
He needs to have the energy to be able to mould players, know that the players are listening to him and have the authority to ensure that this is happening.
He realises that, at Chelsea, he needs to control the agenda as much as possible - something he could not do at PSG.
Most importantly, he needs to get the message across that this will not be a quick fix and, more than vast sums of money, what is required most is time.