Celtic have confirmed chief executive Peter Lawwell has chosen to retire at the end of the 2020-21 season and he will be replaced by Scottish Rugby's Dominic McKay.
Lawwell will bring to a close a spell of 17 years in charge at Parkhead where he has overseen unprecedented success, winning 29 trophies, 13 league titles and four domestic trebles.
'It has been an enormous privilege to have served the club and our supporters for more than 17 years – a wonderful honour to have been part of an institution I have loved and supported all my life,' Lawwell said in a statement.
'I will always be very proud of what we have achieved together and it has been a particular privilege to be involved throughout a period in the club's history which has brought immense domestic success - as well as so many great European nights at Celtic Park.'
McKay, current chief operating officer at Scottish Rugby, accepted the post to replace Lawwell for next season after 13 years with Scottish Rugby.
He said that the opportunity to take over at Celtic was one he felt was too good to turn down.
McKay said: 'Joining Celtic FC as chief executive is a once in a lifetime opportunity and a new challenge I am very excited about taking on later this year.
'I have been incredibly impressed with the vision and people within the club and I look forward to working with them.'
Lawwell was particularly complimentary of the decision to hire McKay as his successor given his work with Scottish Rugby since 2015.
'Dominic will inherit a first-class executive team and a superb group of colleagues,' Lawwell added.
'I am grateful to them all for the backing I have received during the past 17 years. I have also owed a great deal to the unstinting guidance and support from Dermot Desmond, someone who has been so fundamental to our success on and off the field.
'In addition, I thank our present chairman Ian Bankier, previous chairmen and board members I have worked with, as well as Neil Lennon and the other five football managers and their backroom teams and, of course, so many great players at Celtic Park across the years who have given me and our supporters so much pleasure through a sustained period of success.
'I know that they will provide the same unwavering support and help to Dominic as they help to build on our past success.'
He added: 'I believe the club have identified an excellent successor with the highest integrity who will bring substantial experience and enthusiasm to the role.
'Like every Celtic supporter, I am disappointed that, so far, this season has not worked out in the way we all hoped for, despite our best efforts.
'My goal will be to work with Dominic in order to make changes as smoothly as possible and maintain a focus on continued success on the field of play. Together, our main priority will now be to ensure a seamless transition.'
This season has been far more difficult to navigate for Celtic than most, not least because they are already 23 points behind bitter rivals Rangers in the title race.
But off the field Lawwell was left to tackle the club's embarrassing episode of a warm-weather training camp in Dubai in the middle of a global pandemic.
Celtic were given permission by the government to go back in November but despite cases rising they pushed ahead with the trip in December after losing to Rangers in the Old Firm derby.
A positive test in the first-team playing squad - defender Christopher Jullien - led to 13 players and coaches forced into isolation through track-and-trace in what became a fiasco Lawwell was left to apologise for.
In an in-house interview released earlier this month, Lawwell expressed his regret that the trip had gone ahead - while detailing the thought process behind it.
'Looking with hindsight, looking at the outcome of the trip, clearly it was a mistake and for that I profoundly apologise to our supporters,' he said.
'We left here and the rationale for the camp was with the very best of intentions. Things haven't gone the way we wanted to, and the outcome is clearly very regrettable.'
Asked why the trip went ahead in the first place, Lawwell continued: 'If you look back over the last four years, going to the camp in Dubai has been extremely successful.
'The decisions we made are entirely for the best interest of the team and the best interest of the club.
'What we planned to do was take them to these facilities again - which are world class - after a very, very hectic programme in November and December, which has in the past proven to be of great benefit in terms of performance after January.'