Terry Cobner, the Welsh Rugby Union's Director of Rugby, has retired.
The former Pontypool and Wales captain joined the Union in 1996 as the first man in the newly-created position.
The 58-year-old has stood down for 'personal reasons' and will officially leave his post next week.
No successor is likely in the short term while the WRU general manager Steve Lewis conducts his strategic review of the Union's Directorate.
Cobner, who won two Grand Slams and three Triple Crowns during a 19- cap Test career, said: "I've spent the best part of 40 years working in rugby as a player, coach, selector and administrator and I feel the time is right for me to step down.
"I'm fiercely proud of Welsh rugby and I'm proud of the contribution I have made to the game that has given me so much in my life. But now is the time for me to put my family first.
"I've thoroughly enjoyed the eight years I've spent heading up the Directorate at the WRU and I feel we have made massive strides since 1996.
"Welsh rugby now has a very capable, nationwide network of development officers who are working to enhance and nurture our national game from grass roots level upwards and I firmly believe we are moving in the right direction.
"Let's face it, the game has seen tumultuous change over the past 10 years and is unrecognisable from when I was playing.
"If we haven't always managed that change well, the signs are there for all to see that we now have strong, professional leadership in Wales and a structure that merely needs time and fine-tuning to bring the best out of our resources."
WRU chairman, David Pickering said: "The contribution made by Terry Cobner to Welsh rugby has been immense.
"It is up there with the all-time greats in the Union's 123 year history.
"There is no doubt that Terry's retirement will leave us with a huge gap to fill at the WRU, but everyone who knows him and his family will fully understand the reasons behind his decision."
England Under-20s suffered a first-ever defeat to their Scottish counterparts on Friday night and head coach Jon Callard admits his young charges will need to put that out of their minds as soon as possible if they harbour hopes of retaining the Under-20s Six Nations title.