In a letter to WRU member clubs, Gerald Davies said he made his decision not to stand for re-election to the board "with considerable sadness".
'On and off the field I hope I have demonstrated my passion and commitment to the game at all levels and I have endeavoured at all times to bring my lifetimes experience and knowledge to help contribute to the well-being of the game and all those who are involved in it throughout Wales as well as on the International stage.
I have always believed and stated that as rugby changes so its organisation must also change anD develop for the common good of all.
I do not wish to sever my ties completely with rugby and will constantly look for opportunities to encourage and support the game that is so dear to my heart.
I will watch with interest how the WRU meets the many challenges ahead."
More top news
A dry night with clear skies across much of Wales. Temperatures will fall widely below zero, so if you're out and about, wrap up!
An orphaned seal pup has been returned to the wild after a spell in RSPCA rehabilitation.
Dutch-owned Abellio Rail Cymru (ARC) has ended its tender for for the next Wales and Borders rail franchise.