Alan Curbishley has been unveiled as the new manager of West Ham.
Curbishley spent 15 years in charge of Charlton
Chairman Eggert Magnusson moved quickly to appoint the former Charlton manager after sacking Alan Pardew on Monday.
"I'm deeply delighted," said Curbishley. "It's a privilege to be here and I'm looking forward to lifting us out of the position we're in."
Curbishley and his assistant Mervyn Day, both former West Ham players, take charge for the first time against Manchester United on Sunday.
Chairman Magnusson said: "I am absolutely delighted that Alan has agreed to join us. He is a manager with a proven track record and real love for this club.
"He did a fantastic job at Charlton and I know how highly regarded he is throughout the football world.
"This is indeed a great day for West Ham United and I am sure that we now have the right management team in place to take the club forward."
Curbishley played for West Ham between 1975 and 1979.
"If you'd said to me when I was at West Ham at the age of 16 that one day I'd be manager I would have thought it impossible," said the 49-year-old.
A poor run of results saw the struggling Hammers slide into the relegation zone and the 4-0 defeat to Bolton prompted Magnusson to sack Pardew.
Curbishley added: "I feel disappointed for Alan Pardew, he is someone I know very well. But this is the world we live in at the moment."
Hammers chairman Eggert Magnusson said he had taken the decision after being shocked by the players' "lack of motivation" in the defeats against Wigan and Bolton.
The Icelander added: "It was a tough decision but it was in the club's best interests."
Born 8 November 1957 in London
Joins West Ham in 1974, making 85 appearances and scoring five goals
Goes on to play for Birmingham, Aston Villa, Charlton and Brighton
Begins managerial career at Charlton in 1991
Addicks are promoted in 1998, relegated the following season but return to the Premiership in 2000
Charlton post their highest-ever finish of seventh in 2004
Following his failure to get the England manager's job, Curbishley leaves The Valley at the end of the 2005/6 season
The new manager is likely to have funds available for new players in the January transfer window, but Curbishley said his first priority was to lift spirits in the current squad.
"If I think we need to spend, we'll do it, but first I've got to meet the players," he said.
"Everyone needs a lift. The players who enjoyed such a good season last year, it's the same bunch and they are better than what they are producing.
"This club has the opportunity to be in the top half of table."
Curbishley, who was interviewed for the England manager's job earlier this year, left Charlton in May after 15 years in charge.
His last game with the Addicks was against United, a team he has never beaten in his career as manager.