South African Rugby Union president Oregan Hoskins has announced he is resigning from his position after over a decade in charge.
Vice president Mark Alexander will serve as the acting president until an election can be held, SA Rugby confirmed.
Hoskins had served as president since 2006 but feels the time is now right to step away.
"I have enjoyed a remarkable 10 and a half years in one of the most high-profile roles in South African sport and have enjoyed some incredible highs," said Hoskins, who advised the membership of SA Rugby at a meeting of the General Council in Johannesburg on Wednesday.
"It has been a pleasure and a privilege and I want to thank everyone involved in South African rugby for the fantastic journey we have shared.
"There have also been plenty of challenges to confront but I wouldn't have wanted it any other way - it's an indication of how much our sport matters in this country.
"At the time of my election I never imagined that I would still be here 10 years later and I look back with considerable satisfaction over what has been achieved in that time. However, over recent months we have faced tough challenges and had some tough conversations which has made me think about my role and my future.
"Being president of SA Rugby has become a full-time job and with my term due to end in 18 months' time I decided that, after a decade in the job, it was now time to start the next phase of my career, although I have no firm plans as yet, and allow someone else to take on this important role."
Hoskins served as vice-chairman of World Rugby alongside former chairman Bernard Lapasset until July of this year when the pair were replaced by Bill Beaumont of England and former Argentina captain Agustin Pichot.