Xavier Gonzalez has left his role as chief executive of the International Paralympic Committee (IPC), the organisation announced today.
The 59-year-old's exit brings to an end a spell at the IPC which began in 2002 as Paralympic Games liaison director.
He became chief executive in 2004 and is credited with transforming the IPC into one of "the most respected governing bodies in world sport".
The IPC said Gonzalez's departure was "part of the next stage in its business evolution" while the Catalan claimed it had become clear that it was time for change.
He will now be replaced on an interim basis by Dr. Mike Peters, with the IPC appointing a recruitment firm to find a permanent successor.
"I was working towards stepping down from the IPC in 2021," Gonzalez said.
"However, after discussions with the Board in January and having achieved pretty much everything I wanted to with the organisation, it became clear that now is the right time for a change of leadership.
"This summer the IPC Governing Board will embark on a new strategic direction and look to maximise the established opportunities out there."
According to the IPC, the Bonn-based organisation was on the brink of bankruptcy when Gonzalez took over, employing just 10 people.
There are now 115 staff with regular turnover of €20 million (£17 million/$22 million) a year.
Gonzalez's tenure included eight Paralympic Games and saw improvements in spectator numbers, TV audiences and athletic performance.
Better relations with the International Olympic Committee is seen as another plus, including last year's partnership agreement between the two bodies which will run until 2032.
"It has been an absolute privilege and honour to have served the IPC, the Paralympic Movement and Para-athletes for the last 17 years," Gonzalez said.
"This role has not just been a job, but my passion and my life providing many memorable and thoroughly enjoyable life changing experiences.
"I am extremely proud of what I have helped to deliver with the support of the outstanding team and dedicated network of volunteers since 2002.
"To see the evolution of Para-sport and the development and growth in global recognition of Para-athletes around the world has been amazing.
"Para-athletes really are now seen as sport stars who deliver mind-blowing performances few thought possible years ago.
"The level of media and broadcast coverage they now secure, as well as the commercial support within the Movement, really is a far cry from what it used to be.
"It's also amazing to see the size and global reach of the IPC and Paralympic Games now compared to when I joined when we had no money and employed just a handful of people.
"I leave the IPC in a very strong position and well equipped for its next stage of development.
"I wish the team under the interim leadership of Mike Peters all the very best for the future."
Peters is a two-time Paralympian in cerebral palsy football, who joined the IPC as chief of staff in 2015.
The American became chief operating officer last year.
"There are few words that can properly do justice to the impact Xavier has had on the IPC and the Paralympic Movement," said IPC President Andrew Parsons, who replaced Sir Philip Craven in 2017 as the Briton stepped down after 16 years.
"Under his leadership, he has done an outstanding job, effectively building the IPC from a start-up to a globally well-respected sports organisation.
"The IPC Governing Board will always be grateful to his contribution in progressing the Paralympic Movement.
"Xavier will continue to support the IPC with the delivery of the Paralympic Games until 2020 and we are working on the best ways of facilitating this."