Ospreys coach Lyn Jones has stepped down after claiming to have taken the Welsh region as far as he can.
Jones, who has led the Ospreys since their inception in 2003, steered the Celtic League outfit to Anglo-Welsh Cup glory and the quarter-finals of the European Cup this season.
He said: "I take great satisfaction in our many achievements over the past five years.
"The region now stands as one of the leading sides in European rugby and that is something that I know everybody involved at the Ospreys is proud of.
"Having achieved the success, I feel its now time to get my teeth into a new challenge and look for fresh horizons."
The star-studded Ospreys were left bitterly disappointed by their European Cup exit at the hands of unfancied Saracens, leading to speculation over Jones' future.
Their failure to challenge for the Celtic League title - they finished seventh, 24 points behind winners Leinster - further damaged his chances of continuing as head coach.
Jones added: "I believe with my job firmly done at the Ospreys it is the best time for a new hand to come in and move the team on to the next level of development."
Ospreys elite performance director Andrew Hore will lead the hunt for Jones' replacement.
Hore, who arrived at the Liberty Stadium in March, has spent the last two months conducting a wide-ranging review of the region.
Assistant boss Sean Holley and forwards coach Jonathan Humphreys will continue under Andrew Hore's guidance.
Ospreys managing director Roger Blyth said: "Our challenge now is to recruit a coach of worldwide calibre capable of picking up the reins from Lyn.
"Our focus will be on an individual of outstanding ability, professionalism, leadership and innovation with the capability of taking the squad on to the next level.
"We want the right man for the job and we are prepared to look hard and fight hard to get him."