Gary Hamilton has parted ways with Glenavon after almost 12 years as manager of the Mourneview Park club.
The Lurgan club confirmed that Hamilton had "vacated the post with immediate effect" after discussions this week.
Glenavon have started the season poorly, having won one and drawn one of their first seven Irish Premiership games to lie 11th in the table.
Hamilton led the club to Irish Cup victories in 2014 and 2016 and four third-place finishes in the league.
"The Board of Directors sincerely thank Gary for his twelve years as manager. The Hamilton era included many memorable moments which will be part of our club's history including two Irish Cup triumphs, four 3rd place finishes in the Premiership and European qualification on four occasions," read a statement released by the club on Wednesday evening.
"The Board wishes Gary every good fortune in the future."
The former Northern Ireland international was appointed to the post in December 2011 as his boyhood club struggled at the foot of the table.
He set about reviving the club's fortunes and those two Irish Cup final wins over Ballymena United and Linfield in the space of three seasons proved to be the highlight of his time in charge.
In recent campaigns however, the Lurgan Blues have struggled to match the achievements of the early part of the 42-year-old's tenure as investment has flowed into other clubs in the top flight of Northern Ireland football.
Despite that, Hamilton guided the mid-Ulster outfit to seventh place in each of the last four terms and achieved a regular place in the play-offs for qualification for European competition in the process.
Glenavon endured a 10-game run without a win at one stage last season, but their form improved in the latter stages of the campaign as they picked up seven wins and three draws from their final 10 league matches.
Regular early exits in cup competitions have been a feature of recent years however, including an Irish Cup sixth round defeat to H&W Welders and a League Cup round of 16 loss to Loughgall in the 2022-23 season.
Hamilton helped nurture a stream of exciting talent during his time at Mourneview but lucrative financial offers from other clubs and the lure of moves to full-time football in Northern Ireland or beyond saw him lose the services of the likes of Shayne Lavery, Bobby Burns, Mark Sykes, Josh Daniels, Rhys Marshall, Caolan Marron, James Singleton and Matthew Fitzpatrick.
Glenavon started the present term with defeats by Glentoran, Cliftonville, Linfield and Newry City, before earning a point on the road at Loughgall and their first win against Ballymena United.
That was followed by a 3-1 reverse at the hands of fellow strugglers Dungannon Swifts on Saturday.
Assistant Manager Paul McAreavey and coaches Mark Ferguson and Chris Acheson have resigned their positions with the club.