This is a story about an inspirational mule called Wallace the Great, who has shaken the staid British equestrian scene to its very hoofs.

Wallace, whose sire was a donkey and dam was a horse, comes from a humble background. He was found wandering the streets in Ireland, living off scraps and flowers from village gardens (much to the chagrin of residents), and rescued by a British donkey sanctuary.

But 11-year-old Wallace’s life changed dramatically after he met Christie Mclean, from Stroud in Gloucestershire. Ms Mclean competes in entry-level dressage – and had her own problems when all of her horses went lame.

This was Wallace’s time to shine – and he and Ms Mclean paired up to learn the delicate movements of dressage. But when they wanted to enter a British Dressage-affiliated competition last weekend, the pair was denied their chance – because Wallace is not a horse.

Wallace and Ms Mclean share a moment before competing. Photo: Facebook

It was a huge blow, especially as Wallace and Ms Mclean had already done well in local competitions.

“When British Dressage said the rule book only refers to horses and ponies within its affiliated criteria, I was really surprised and disappointed,” Ms Mclean told the BBC.

“I don’t think it’s a case of equine racism but more a case of the rule book being very out of date.”

News of the discrimination spread across Britain, sparking a public outcry and calls of justice for Wallace the mule.

“It’s got 4 legs, a mane, a seat, why not? Discrimination in the highest order,” wrote one supporter on Twitter.

“Wallace the mule needs justice!!! Mules matter,” wrote another.

Under pressure, British Dressage buckled, changing the rules to allow Wallace – and “all other animals born to a mare” – to fulfil their destinies.

“We are delighted to welcome Wallace and his fellow mules to compete with British Dressage, as part of our commitment to inclusion and diversity in dressage, making the sport more accessible to all,” British Dressage chief executive Jason Brautigam said.

But more momentous news was to come. Not only did Wallace change the course of history for his kind, he went on to win last weekend’s competition.

“He did everything I asked of him … he rode beautifully,” Ms Mclean wrote on Wallace’s Facebook page (where he has more than 6000 followers).

“I cannot thank everyone enough for the huge amounts of support for Wallace, knowing that he has a chance in life makes it even more heart-warming.”

She said history had been made, for mules and for British Dressage, and “wow, was it a good one”.

“I [Christie] fully admit that the pressure was firmly there; we’d come this far and, although I trust Wallace 100 per cent, would I remember to breathe?,” she said.

“But those big ears flop to the side and he’s in work mode – legend.”

Wallace the Great’s future plans are unknown at this stage. But whatever he does next, he is surely already a star.