Everton announced the hiring of Sam Allardyce as their new manager on Thursday, a day after he watched the 4-0 win over West Ham United from the stands.
Discussions between Everton and Allardyce's representatives have taken place since Monday and now the club's six-week search for a replacement for the sacked Ronald Koeman is at an end as the former England manager signed an 18-month contract.
"I'm delighted to confirm Sam as our new manager," owner Farhad Moshiri said in a statement. "His strong leadership will bring great motivation and get the best out of players.
"Sam understands the long-term ambitions we have for this great club and I know he is a man who gives it his all and is focused 24 hours a day on the club."
Everton's dismal run of form under caretaker-manager David Unsworth -- they suffered five defeats in eight games in all competitions -- and their failure to prise Marco Silva from Watford forced the club's majority shareholder Farhad Moshiri to turn to Allardyce.
And Allardyce, who had publicly ruled himself out of the Everton job earlier this month, has now accepted the challenge of steering Everton away from relegation with the club winning just twice in their last 12 games.
The 63-year-old has been out of work since resigning as Crystal Palace manager at the end of last season, with Allardyce claiming at the time that he had retired from management.
But after expressing an interest in the United States job following the departure of Bruce Arena in the wake of the country's failure to qualify for the 2018 World Cup, Allardyce admitted he was open to a return to Premier League management after Koeman's departure last month.
"The attraction of the club itself, the people I've known at the club -- Peter Reid is one of my best mates, so are Andy Gray and Paul Bracewell whom I worked with at Sunderland -- these people have always made me aware of just how special and unique a club Everton is and I feel really enthused and energised to come in as manager," Allardyce said in a statement.
"I've always thought Everton was a great club. It is a great club. Obviously, the Club has gone through a difficult spell and hopefully I can put that behind us as quickly as possible and start looking upwards again."
Sources have told ESPN FC that Allardyce is keen to appoint former Leicester boss Craig Shakespeare, who worked under the 63-year-old during his brief spell as England manager, as his assistant at Everton.
Everton also confirmed that Unsworth will return to his previous position as the club's under-23s manager and academy director.
Information from Mark Ogden was used in this report.