Olympic individual champion Nick Skelton believes that "now is the right time" to retire from showjumping.
British Showjumping announced on Wednesday that 59-year-old Skelton and his Rio Olympics gold medal-winning ride Big Star will formally retire at the Royal Windsor Horse Show on May 14.
Skelton won Olympic individual gold last August, while four years earlier at the London Olympics he helped Great Britain to team gold alongside Scott Brash, Ben Maher and Peter Charles at Greenwich Park.
He recovered from a broken neck in 2000, returning to the saddle barely two years later, before achieving his number one ambition of Olympic individual gold eight months ago.
"I've been thinking about it (retirement) over the winter," Skelton told Press Association Sport.
"Big Star is fine and in good order but I think now is the right time.
"For what he has done and what I've done, to finish at the top - you can't get better than Rio - so I decided to call it a day. It has been a gradual decision.
"He has been to stud and he has been successful there, so we are going to go down that route."
Apart from two Olympic golds, Skelton won a World Championship silver medal and four bronzes, plus three European golds, three silver and three bronze.
He was also a mainstay of British Nations Cup teams and won grands prix all over the world, in addition to three Hickstead Derby triumphs and four victories in the King George V Gold Cup.
But it was aboard the brilliant stallion Big Star that Skelton enjoyed his greatest triumph, delivering a showjumping masterclass in Rio last summer.
"I am sure to miss it. 43 years has been a long time jumping internationally, but I will still be around and around horses," he said.
"People are still talking about Rio, which is a great thing. It can't get any better than what happened in Rio.
"Big Star has been the horse of a lifetime. I don't think you will ever see the likes of him again. He has been an absolutely amazing horse and a pleasure to ride. I have been very, very lucky to have him.
"I got closer and closer in terms of the Olympics (and an individual gold medal), and I thought 2016 was going to be the year or not at all. It really worked out well."
In a statement released by BS, Warwickshire-based Skelton said: "Although there are many people, including my family, Gary and Beverley (Big Star's owners Gary and Beverley Widdowson) and my team that were looking forward to us carrying on this year, we feel that Big Star has done everything that a rider could ask and it is time for him to relax and enjoy his stallion duties.
"As for myself, I have always stated that when Big Star was finished I would be as well.
"This sport has given me more than I could have ever hoped over the past 43 years and it is such a difficult decision to make.
"But I am not getting any younger and it is nice for the two of us to end on the highest note possible.
"Thank you to all of the incredible friends and fans for your support - we are truly appreciative and humbled.
"Thank you to all of my owners and sponsors throughout my career, I couldn't have done it without you. And lastly, thank you to all of the horses I've ridden, you have provided me with opportunities one could never have imagined."
Skelton's achievement in Rio was recognised with third place in the BBC Sports Personality of the Year and a CBE in the New Year's Honours list.