Chelsea has parted company with manager Jose Mourinho by mutual consent after weeks of intense speculation over his future.
The defending Premier League champions suffered a fifth defeat in their last seven Premier League games against Leicester City on Monday, when Mourinho said he felt "betrayed" by his players following the 2-1 loss.
MORE: Alex Ferguson's more storied career, in photos | Mourinho feels 'betrayed' by players
Although Chelsea finished atop its Champions League group with a 2-1 victory over Porto last week, the setback at Leicester leaves the Blues 16th in the Premier League table and just one point above the relegation zone after 16 matches.
A club statement said: "All at Chelsea thank Jose for his immense contribution since he returned as manager in the summer of 2013.
"His three league titles, FA Cup, Community Shield and three League Cup wins over two spells make him the most successful manager in our 110-year history. But both Jose and the board agreed results have not been good enough this season and believe it is in the best interests of both parties to go our separate ways.
"The club wishes to make clear Jose leaves us on good terms and will always remain a much-loved, respected and significant figure at Chelsea. His legacy at Stamford Bridge and in England has long been guaranteed and he will always be warmly welcomed back to Stamford Bridge.
"The club's focus is now on ensuring our talented squad reaches its potential.
"There will be no further comment until a new appointment is made."
Last season, Mourinho added a third Premier League title to the two he won in 2004-05 and 2005-06 during his first stint in charge of Chelsea and was rewarded with a four-year contract extension in August.
But the club's fortunes have dramatically dipped since then, with the 52-year-old cutting an increasingly strained figure over recent weeks.
The League Cup holders were also dumped out of that competition courtesy of a penalty shootout loss to Stoke City in October.