The Grand Slam – consecutive wins at the three great five-star horse trials of Badminton, Burghley and Kentucky – has only been won twice since its inception, with Germany’s Michael Jung achieving it at Badminton in 2016, 13 years after Britain’s Pippa Funnell won it at Burghley in 2003.

Townend’s last attempt at the Grand Slam title was Badminton 2018 having won Burghley in 2017 and Kentucky in 2018, but last year’s title was won by Jonelle Price of New Zealand.

The British rider's memories of last year are also clouded by the fact that he lost two sponsors after being penalised for illegal use of the whip during those Badminton trials.

In 2010, having won the Badminton and Burghley events in 2009, Townend was ninth and sixth after the dressage with his two horses Ashdale Cruise Master and ODT Master Rose but fell on the cross country while riding the first horse and had to be airlifted to hospital.

While riders must consecutively win all three events to take the Grand Slam, they are permitted to ride different horses in each competition.

This is important, as the Badminton Horse Trials follow so shortly after Kentucky, and a horse would not have sufficient time to recover between the two competitions, especially since they would have to be flown overseas in that time.

Townend announced yesterday that he would be riding Cillnabraden Evo and Ballaghmor Class at Badminton.

Should he manage to win on Sunday, the Grand Slam would be attainable with victory at this year's Burghley Trials from September 5 to 8.

Meanwhile his British colleague Funnell has named Majas Hope and Billy Walk On.

Price announced yesterday that she would not be defending the title and two other entrants withdrew – Willa Newton of Britain, on Chance Remark, and Germany’s Ingrid Klimke, who decided her 15-year-old, Hale Bob, was not ready to compete.

However, Price’s husband, Tim who finished third behind Townend in Kentucky, will be competing.

Winners of the Grand Slam receive an extra $350,000 (£267,000/€311,000) in addition to their winnings from each event, which at Badminton is £100,000 ($131,000/€116,000).

The first of two days of dressage start tomorrow, with the cross-country phase on Saturday followed by the jumping.