Quarrycrest Echo, with whom Piggy French helped Great Britain to the eventing team gold medal at last year's World Equestrian Games (WEG) in Tryon, has been sold to Japan.
As reported by Horse & Hound, the 12-year-old has been bought from owner Jayne McGivern by Riding Club Crane for Toshiyuki Tanaka to ride.
Quarrycrest Echo, known as "Red" at home, has been one of Britain’s most successful event horses in recent years.
As well as taking the team gold medal at the 2018 WEG, he and French were also members of the British team which won silver at this year's European Championships in Luhmühlen in Germany.
"Jayne McGivern and I are very sad to announce the sale of Quarrycrest Echo to continue his career with Toshiyuki Tanaka and Team Japan," French said in a statement.
"'Red' has been an absolute superstar for both of us over the past few years, taking us all over the world to some of the biggest and best events in our sport.
"Firstly, I would like to thank 'Red' for everything he has given me as my friend and partner in all the great days we enjoyed together.
"Secondly, I would like to thank Jayne for her tremendous support both past, present and future.
"She has been instrumental in helping me achieve my goals after the last few years and we are both looking forward to many more years of success together."
French added: "This was a very difficult decision for both of us, but we would like to wish Toshi and Team Japan the very best of luck with him in 2020 and beyond.
"He has been an outstanding horse for Jayne and I and we sincerely hope he is the same for his new connections.
"'Red’s' departure will without doubt leave a big hole in my yard, but I am fortunate to have some lovely horses, both old and new, who I believe can step up to fill the gap he leaves behind.
"Twenty-twenty is a huge year for me and everyone else in our sport and I am hugely excited and motivated to continue my preparations towards representing Team GB at the Tokyo Olympics.
"Thank you, 'Red', for everything. Piggy x"
French and Quarrycrest Echo won the Concours International Combiné three-star event in Chatsworth last year and the Concours Complet International (CCI) four-star competition in Hartpury this year, after finishing second there in 2018.
"Probably my very best memories of him are winning the Event Rider Masters class at Chatsworth in 2018, and of our win at Hartpury in the CCI4*-S this year," French told Horse & Hound.
"He is the most incredible horse to ride at speed round a shorter track – I’ve never had one like it - and I’m so proud of him.
"He has been such fun to ride and I am very fond of him."