West Ham have appointed one of the world's "most respected" football coaches in Manuel Pellegrini, according to joint chairman David Sullivan.
Pellegrini, 64, has signed a three-year deal at the London Stadium.
The former Manchester City and Real Madrid manager left his job with Hebei China Fortune over the weekend and succeeds David Moyes.
"Manuel brings a reputation for attacking football and getting the best out of his players," said Sullivan.
"We believe he will attract new talent to the London Stadium as well as improving the current squad.
"Manuel is the first West Ham United manager to have a Premier League title on his CV, and we believe his experience, quality and proven record of taking teams forward quickly will ensure that he is successful here."
Chilean Pellegrini, who had been a priority target from the start of West Ham's search for a new manager, will be joined at London Stadium by assistant Ruben Cousillas.
He replaces former Everton and Manchester United manager Moyes, who was appointed West Ham boss in November 2017 but released at the end of his contract after guiding West Ham to 13th place.
West Ham had explored the possibility of hiring Newcastle United manager Rafael Benitez, however they quickly concluded it would be hugely difficult for the Spaniard to leave St James' Park.
Pellegrini, who was on a huge contract in China, has agreed to take a pay cut but it is anticipated he will become the highest paid manager in West Ham's history.
Sullivan had previously said he intended to hire someone who had experience at the highest level.
Pellegrini won the 2013-14 Premier League title and two EFL Cups during his three years at Manchester City, in addition to taking the club to the Champions League semi-finals.
West Ham have experienced huge problems during their first two seasons after leaving Upton Park.
They won just seven home Premier League games this season, a campaign which was marred by crowd trouble at London Stadium.
Five fans were banned for life by the club for running on to the pitch during their home fixture with Burnley on 10 March.
Other fans were also banned for life for throwing coins or objects "with intent to injure or harm".
Southampton Reportedly Decline Opportunity to Sign Troubled Schalke Starlet
Schalke 04 star Max Meyer is looking for a new club this Summer, but will not be going to relegation candidates Southampton, who have reportedly turned down the opportunity to sign the troubled attacker.
Since deciding on not signing a new deal in February, Meyer has seen little first team action. His last appearance for Schalke came on the 15th April in a 2-0 victory over Borussia Dortmund.
The 22-year-old is currently suspended for criticising Heidel, after Meyer accused Schalke of bullying him.
Meyer told Bild: “I was never concerned about the money, otherwise I would have accepted the second improved offer.
“That’s why I find it a mess for Clemens Tonnies to say it on TV as if it were all about money. I simply did not want to stay with Schalke and work under Heidel. It’s all about this. Lately, it just feels like bullying to me.
“I did not want to come out and talk. I’ve just had enough of always reading something about myself, but neither Heidel nor Tonnies talked to me. Now they can read how the last two years have been for me at Schalke.”
There is little good to come from this story for both Southampton and Meyer. Southampton are not necessarily in need of such a player, while Meyer has no doubt tarnished his reputation through this bizarre story.
Bild have suggested that Southampton may have been put off by the player asking for a signing-on fee of around €10m.
Ferguson's family have requested privacy as he recovers in Salford Royal Hospital.
"We will keep Sir Alex and his loved ones in our thoughts during this time, and we are united in our wish to see him make a comfortable, speedy recovery," United later said in a tweet.
"He needs a period of intensive care to optimise his recovery."
The most successful manager in the history of the British game, Ferguson's trophy haul at Old Trafford included 13 Premier League titles, two Champions League crowns, five FA Cups and four League Cups.
Ferguson famously won the Treble of Premier League, FA Cup and Champions League in 1999, the year in which he was knighted.
United's club captain Michael Carrick said he was "devastated" to learn his former manager had needed emergency surgery.
"All my thoughts and prayers are with him and his family. Be strong boss," he posted on Twitter.
Ferguson has been married to wife Cathy since 1966. His son Darren manages Doncaster Rovers but did not not take charge of their League One match against Wigan on Saturday.
Ferguson began his playing career with Scottish club Queen's Park as a 16-year-old striker while working as an apprentice tool-worker at Clyde Shipyards.
His most notable spell as a player came in a two-year stint at Rangers from 1967. He retired as a player in 1974 when he was on Ayr United's books.
He began his managerial career as a 32-year-old at East Stirlingshire before going to St Mirren, where he won his first trophy by taking the Scottish first division title in 1977.
Ferguson moved on to Aberdeen and turned them into a major force in a Scottish top division in which Rangers and Celtic had dominated.
He led them to three Scottish titles, four Scottish FA Cups, one League Cup and the European Cup Winners' Cup in 1983 by beating Real Madrid 2-1 in the final.
Conte praises 'fire in our eyes' after Chelsea comeback stuns Southampton
Chelsea manager Antonio Conte says his team showed "the right fire in our eyes" as they mounted a remarkable comeback from 2-0 down to win at Southampton.
The victory - thanks to three goals in eight second-half minutes - kept alive their faint hopes of a top-four finish in the Premier League.
Dusan Tadic's opener, a placed effort following Ryan Bertrand's marauding run, and Polish defender Jan Bednarek's left-footed shot looked to be lifting Saints out of the bottom three.
But, with Mark Hughes seemingly on course for a first league victory as Southampton manager since arriving on 14 March, the entrance of substitute Olivier Giroud, who scored twice, sparked a listless Chelsea into life.
The France forward's header - his first league goal for Antonio Conte's team - and left-footed drive sandwiched Eden Hazard's left-foot finish as the Blues moved within seven points of fourth-placed Tottenham.
"I was very angry from our first half," Conte said. "In the second half we showed great character, great determination and desire to win the game. We showed the right fire in our eyes."
For an hour, Chelsea's performance epitomised their travails since the turn of the year, with the defending champions having collected just 12 points from the previous 33 available.
Willian's 55th-minute shot was their first effort on target, and there were question marks over the application of several players in the build-up to both Saints goals.
One of those players - wing-back Marcos Alonso who crossed for Giroud's header - was also fortunate to escape without punishment for standing on the back of Southampton forward Shane Long's calf in the first half.
The incident left the Southampton manager furious and calling for the Football Association to take retrospective action, which could potentially rule Alonso out of next Sunday's FA Cup semi-final rematch between the clubs.
"It was a poor challenge, it should have been a red card in my view," Hughes said.
"I don't think he was booked, so maybe people need to look at that again, retrospectively. Thankfully he's just about OK, but he's been raked down the calf.
"We're not here to accuse people, and no sour grapes, but a decision needs to be made on that because it's not acceptable."
Southampton remain 18th as they try to avoid slipping into the Championship for the first time since 2011-12.
No respite for Southampton or Hughes
After being sacked by Stoke, Hughes is facing the ignominious prospect of playing a part in the relegation of two clubs this season.
The upturn in results the Saints board hoped for when the Welshman was brought in to replace Mauricio Pellegrino just over a month ago has not materialised.
While an FA Cup semi-final against Chelsea is on the horizon, Hughes has presided over three successive league defeats, with three goals conceded in each match.
Following an abject 3-0 defeat at West Ham, there were encouraging signs in a 3-2 defeat at Arsenal last Sunday, and more of the same against Chelsea.
Southampton controlled proceedings for about 70 minutes, but their biggest problem is turning performances into points.
"Some of our guys are up for what we've got ahead of ourselves," Hughes said.
"I'm learning about the group more and more each training session and match. We're still conceding goals and they're just slips in concentration."
One victory in 20 league matches - against bottom club West Brom - does not bode well for the Saints though, who could be six points adrift of safety later.
Conte changes the flow
Much of Chelsea's display typified the problems that have undermined their defence of the title and have been exacerbated by speculation over the future of Conte.
The Italian has not helped himself at times, allowing himself to become embroiled in a public spat with Manchester United counterpart Jose Mourinho and at times cutting a desolate figure on the touchline.
There was again an absence of emotion and touchline theatrics that marked first season at Stamford Bridge, but Conte did turn this contest on its head with the introduction of Giroud and Pedro.
"In the first half we didn't play well but not just that, they put more into the tempo than us," Conte said.
"The most important thing is to show in every game the right passion and to fight until the end. We need to finish this season in the best possible way.
"I don't know why the desire wasn't there but the coach is the first person to have the fault. It doesn't matter that we won the game 3-2, it was important to see the right reaction and fight in the eyes of my players."
Chelsea had lacked conviction in front of goal until Giroud replaced Alvaro Morata, while Davide Zappacosta had a largely forgettable afternoon before being withdrawn for Pedro.
The former Torino man was caught out of position for Tadic's opening goal and had just 11 touches in Southampton territory during the first period.
By contrast Ryan Bertrand created the opening goal for Saints and appeared to be almost permanently stationed in the Chelsea half, having 23 touches.
Giroud, though, made the difference - scoring twice from his two efforts on goal.
Man of the match - Olivier Giroud (Chelsea)
'Super-sub Giroud' - the stats
Southampton have lost consecutive Premier League games after scoring two or more goals for the first time ever.
Chelsea have won a Premier League game from two goals down for the first time since August 2002 under Claudio Ranieri (3-2 v Charlton).
Hughes is only the second manager to lose three Premier League games against the same opponent in a single season after Graeme Souness vs Arsenal in 2004-05.
The Blues have won five in a row against Saints in the league for the first time ever.
Tadic has been directly involved in 45 Premier League goals since his debut in August 2014 (18 goals, 27 assists), 14 more than any other Southampton player.
Bednarek is only the third Polish player to score in the Premier League, after Robert Warzycha in 1992 and Marcin Wasilewski in 2015
Giroud has netted 19 goals in the Premier League as a sub, a haul only Jermain Defoe can better (24).
Giroud is also the top-scoring sub in the Premier League this season, with six goals from the bench.
Giroud is the first player to score an away goal against the same opponent for different clubs in a single Premier League season since Mikel Arteta (for Everton and Arsenal v Blackburn 2011/12).
Hazard has scored 69 Premier League goals for Chelsea; only Frank Lampard (147) and Didier Drogba (104) have netted more.
Both clubs play again before facing each other in their FA Cup semi-final at Wembley on 22 April (15:00 BST). Southampton travel to Leicester City on Thursday, 19 April (19:45 BST kick-off), while Chelsea visit Turf Moor to play Burnley on the same evening (19:45 BST kick-off).
The players - Gareth Barry, Jonny Evans, Jake Livermore and Boaz Myhill - were questioned but not arrested by police, and look to have avoided legal action because of a lack of evidence.
Pardew, who has also managed Reading, West Ham, Charlton, Southampton and Newcastle in an 18-year managerial career, has lost two FA Cup finals as a manager.
He was named League Managers' Association Manager of the Year in 2012 after Newcastle finished fifth in the Premier League.
However, he has also been involved in various controversies during his career.
While West Ham boss in 2006, Pardew was involved in a confrontation with Arsenal manager Arsene Wenger, and in January 2014 he swore at Manchester City boss Manuel Pellegrini while at Newcastle.
Two months after that, he was fined £100,000 and given a formal warning for headbutting Hull City midfielder David Meyler.
'Guardiola would be sacked with this record'
Adrian Chiles, BBC Radio 5 live presenter and West Brom fan
If you'd told me we'd be at this stage looking at our third manager of the season after just three wins I'd have said that was far-fetched.
But it had to happen. You just can't lose as many consecutive games. If we'd had Pep Guardiola in and he'd lost that many games, we'd have had to get rid of him - that's just the way it is.
I don't think anyone could accuse the board of being a quick-firing operation, I just think if anything it's too late.
I'm sure Pardew's had enough, poor man, along with his assistant, and maybe the club have identified someone that can come in now and have a look at the squad before next season, have them over the summer and do something in the Championship.
Darren Moore is a club legend and he'll have a lot of goodwill behind him. He can't get any worse. I must say with Pardew I can't celebrate him going because I found him to be a decent bloke and we looked to be improving when he took over.
Nothing seemed to go right, the gods of football were against us. I don't know who could've come in and changed things around after Tony Pulis left.