Steve Bruce has left his position as Hull City manager by mutual consent amid claims he became frustrated by a lack of transfer activity at the club.
Reports on Friday suggested Bruce - a candidate for the England job that eventually went to Sam Allardyce - had walked out after a failure to strengthen his squad, which has been hit by numerous injuries during pre-season.
And the club later announced the departure of their most successful manager, who oversaw a return to the Premier League via the play-offs last season.
"Following four incredible seasons with the Tigers including two promotions and our first ever FA Cup final, we can confirm that manager Steve Bruce has left the club by mutual consent," a club statement read.
"The Board of Directors would like to thank Steve for all his efforts since his appointment in 2012 culminating in a glorious day at Wembley in May which saw the club bounce back into the Premier League.
"Steve has excelled in his role - both on and off the field - and will be remembered for being the most successful manager in our history to date.
"Steve Bruce wishes the club and the owners all the very best for the forthcoming Premier League season.
"Steve also wishes to place on record his thanks to the club's supporters for their unwavering support and also to all the players and staff who have worked with him during his time at the KCOM Stadium."
Assistant Mike Phelan, who is among the favourites to take over the job on a permanent basis, has been placed in caretaker charge as Hull continue their pre-season preparations.