The Rolex Grand Slam of Eventing is the richest and most sought-after prize in the sport, and the world’s number one event rider, Britain’s Oliver Townend, has a fighting chance of becoming only the third person ever to capture it at Mars Badminton Horse Trials next week (9-12 May).

To win the $350,000 (£230,000) Rolex Grand Slam of Eventing, a rider must take first prize at the three most challenging CCI5* competitions across the globe – Defender Burghley Horse Trials (UK), the Defender Kentucky Three-Day Event (USA) and Mars Badminton Horse Trials (UK). They must be won consecutively, but in any order and on multiple horses.

Shropshire-based Oliver, 41, won Defender Burghley last autumn on Karyn Shuter, Val Ryan and Angela Hislop’s Ballaghmor Class, and last weekend he took Defender Kentucky on Paul and Diana Ridgeon’s Cooley Rosalent. Ballaghmor Class is Oliver’s ride at Mars Badminton – and the 17-year-old grey, who was part of Britain’s gold medal-winning team at the Tokyo Olympics in 2021, finished second at the Gloucestershire event in 2023.

Oliver said: “Over the years I’ve kept thinking to myself, I’m never going to mind losing Grand Slams because to be in the position of trying to win one means you’ve already won the most important competitions in in the world. It’s a huge privilege to be the only rider to have got into that position three times; on the first occasion [in 2010] I left the event in an ambulance, and the second time [in 2018] I finished second, so I’m hoping it’s third time lucky.

“I think the Rolex Grand Slam of Eventing is the most difficult thing to win in any sport, not just ours, because as riders we are so reliant on our partners, the horses, and they of course are characters and athletes in themselves.

“Ballaghmor Class is very special to me. I have had him since he was four years old, so we know each other inside out, and he’s already won me an Olympic team gold medal and three of my eight CCI5* victories, most recently Defender Burghley last September. I think the conditions at Badminton next week should suit such a tough, brilliant horse very well, and we will give it our best possible shot.”

Irish statistics company EquiRatings make Oliver and Ballaghmor Class second-favourite on ratings to win Badminton, and therefore the Rolex Grand Slam, just behind former World Champion, current European Champion and reigning Badminton Champion Ros Canter (this time riding Izilot DHI).

EquiRatings’ Diarmuid Byrne said: “Ballaghmor Class has already pulled off two of the best four dressage tests recorded at Badminton over the past 15 years and given his proven ability both at Badminton and at the highest level of the sport in general, by the end of cross-country day next Saturday it is very likely that Oliver and Ballaghmor Class are favourites to win.”

Britain’s Pippa Funnell was the first ever winner of the Rolex Grand Slam of Eventing, completing her hat-trick at Burghley in 2003. The great German rider, double Olympic gold medallist Michael Jung, is the only other person so far to have pulled off this immense challenge, winning his Rolex Grand Slam of Eventing at Badminton in 2016.