Aitor Karanka has left his role as manager of Nottingham Forest after the club agreed to release him from his contract.
Speculation has been building over recent weeks that the Spaniard's days at the City Ground were numbered, amid rumours of a major fall-out with the club's hierarchy.
Karanka was appointed in January last year, having been sacked by Middlesbrough in March 2017 with the club heading for relegation from the Premier League.
His last game in charge of Forest was Saturday's 2-0 FA Cup third-round defeat at Chelsea.
His most recent Championship outing was an impressive 4-2 defeat of leaders Leeds United on New Year's Day, a triumph which ended a five-match winless run and leaves Forest just one place and four points outside the play-offs.
"Aitor Karanka has asked to be released from his contract as the manager of Nottingham Forest Football Club," a brief statement on the club's official website read.
"The club have agreed to this request and the terms of departure have been agreed. Both parties wish each other every success for the future. There will be no further comment from either party.
"Simon Ireland will take charge of first-team affairs until a new manager is appointed."
Karanka took in 52 games at the Forest helm.
He only emerged victorious in 16 of those, drawing 19 and losing 17.
That inability to deliver positive results has contributed to his departure, but managerial change has been commonplace at the City Ground in recent times and the Reds are preparing to open another new chapter.