Hull KR head coach Justin Morgan will leave the club at the end of this Super League season.
The 36-year-old moved to Craven Park from Toulouse in 2005 and guided Rovers into the top flight a year later.
However, the Australian has been linked with a move away from the club for most of this season, with Castleford thought to be his most likely destination.
"Both parties genuinely believe now is the right time for a change," Rovers chairman Neil Hudgell said.
He added: "With bringing things out in the open we can accelerate those plans.
"Justin should be rightly proud of his achievements.
"Personally it's a sad time for me as we have a great relationship and enjoyed some great times rebuilding this club, but I also think it is the right time for both parties to move on."
Morgan was only 29 when he took up his Rovers role and led them to National League One glory in his first full season in charge with a victory over Widnes in the 2005 Grand Final.
He kept the club in the Super League in 2007, effectively securing them a Super League licence for the 2009-11 period.
They reached the play-offs in each of the last two seasons but will struggle to do so this year, with poor form and off-field troubles, most notably the Willie Mason saga.
"I think it's time (to go)," Morgan said.
"The club has given me a great opportunity and I have thoroughly enjoyed my time here.
"I have always enjoyed an open relationship with Neil and the board, to the point that the club has been supportive in giving me permission to talk to other clubs about coaching positions, despite the fact that I am under contract."
As well as the vacant position at Castleford, Morgan has been been linked with jobs at New Zealand Warriors and NRL outfit Penrith.
Morgan's assistant at Rovers, Andrew Webster, is a potential successor, as is his brother James, who is assistant at Hull FC and was captain of Morgan's title-winning team.
Outgoing Wakefield boss John Kear is also likely to be in the frame.