David Moffett is to leave his post as Welsh Rugby Union group chief executive later this year.
Moffett's surprise announcement comes as the WRU embarks on its 125th anniversary season, complete with record profits and a national team basking in glory as RBS 6 Nations Grand Slam champions.
During Moffett's reign, Welsh rugby witnessed a radical overhaul, highlighted by the formation, initially, of five professional regional teams.
That figure has since been reduced to four following the demise of Celtic Warriors, with the Newport-based Dragons, Cardiff Blues, Ospreys and Llanelli Scarlets now flying the Welsh flag in Celtic League and European Cup competitons.
''I have loved my time in Wales, and I feel a particular affinity with the Welsh people,'' said Moffett, who will leave the WRU on December 31.
''I am returning to live in New Zealand because of personal and family reasons. I have no professional plans.''
The WRU, meanwhile, have revealed that they have no immediate plans to appoint a successor.
''On behalf of the WRU Group, I must put on record our grateful thanks to David Moffett for his outstanding contribution to the WRU Group over the past three years,'' said WRU chairman David Pickering.
''He has made a huge difference to the business of the WRU Group, and to the fortunes of Welsh rugby, both on and off the field.
''David has been fundamental in securing an extremely strong management team within the WRU Group, and therefore, it is not our intention as the board of directors to appoint a new Group CEO for the foreseeable future.''
Peter Hain, secretary of state for Wales, said: ''David Moffett leaves with the heartfelt thanks of Welsh rugby supporters.
"He has brought his own standard of professionalism to the Welsh game. He leaves it in much better shape than when he started.
"I don't think Wales could have won the Grand Slam without the administration he put in place.''
England flanker James Haskell insists he will be pushing as hard as possible to be back from a toe injury in time to make his case for a spot in Eddie Jones' side looking to defend their RBS 6 Nations title next year.