The England and Wales Cricket Board have confirmed that Hugh Morris will step down from his position as managing director with immediate effect.
Morris joined the organisation back in 1997 at the end of his playing career with Glamorgan.
However, after 16 years in various different roles, the 49-year-old has opted to return to his former county, where he will shortly be announced as their chief executive and and director of cricket.
"This has been a remarkable period in the history of cricket in England and Wales and I have been extremely proud to having been able to play a part in it," he said in a statement.
"In my time at the ECB I have been fortunate to work with some extremely dedicated and talented cricketing people and I thank them and the board all for the support they have given me and their contribution to the success of the England teams.
"I am now looking forward to a new and exciting challenge with Glamorgan which I will tackle with energy, enthusiasm and relish. I wish the England teams at all levels and the ECB the very best of luck in the coming years and I am sure they will enjoy further success."
The ECB's chief executive, David Collier, went on to add that a replacement for Morris would be announced in the near future.