The moment of horror as Zara Phillips is thrown from her horse

She crash-landed on her neck and shoulders after her horse, Tsunami II, stumbled over a 7ft fence at a three-day event.

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The crowd gasped in horror as Zara, 26, who is 11th in line to the throne, tumbled over the mare's head and on to the turf.

She was thrown forwards and struck the ground with a sickening thump, said witnesses at Bramham International Horse Trials near Wetherby, North Yorkshire.

Zara rolled over several times before sitting up, looking dazed.

Stewards rushed to help as her horse picked itself up and cantered away along the cross-country course.

Astonishingly, Zara was unharmed and walked off the course, smiling wryly. But she withdrew from the competition and was not taking part on the third day today, the showjumping section.

However, she was planning to compete in Luhmuhlen, Germany.

"I'm fine – it wasn't as bad as it looked," she said. "The horse caught the fence with her feet, stumbled over it and she nosedived. I tumbled off.

"I'm sore and stiff all over but not at all hurt. Nothing's broken and I feel fine. I'll probably be a lot stiffer tomorrow. I have withdrawn from the competition but I am travelling to Germany for another event and I plan to take part."

Zara was at the event with her father Captain Mark Phillips, who told event-goers he believed the fall at the course's seventh fence was Zara's fault.

Tsunami II is believed to have "banked" the fence – putting her hind legs on top of it, rather than jumping clean over – which meant she landed too steeply.

The Bramham trials are among the most prestigious in British eventing and it was the first time Tsunami II had competed at that level.

The nine-year-old had performed skittishly on Friday in the dressage event, apparently unsettled by the crowds and cameras, leaving Zara in 44th place.

The mare also seemed tense on the cross-country course, probably contributing to the fall.

Zara has been riding Tsunami II for three years and they finished seventh in the indoor cross-country event at the British Open this year.

The European and world eventing champion and BBC Sports Personality of the Year is trying to find a successor to Toytown, the horse that has provided her with most success.

Zara has seven horses at the Gatcombe estate in Gloucestershire where she lives with her boyfriend, England rugby player Mike Tindall.

She will be riding another potential successor, Ardfield Magic Star, in Luhmuhlen tomorrow.

Three years ago she was knocked unconscious in a fall from that horse at a three-day event at Lulworth Castle in Dorset.

Zara is following in the hoof-steps of her mother Princess Anne, who was visiting Northern Ireland. She famously fell off her horse at the Montreal Olympics in 1974.

An eventing source said: "Riders fall off all the time and these girls are very bouncy, but things can sometimes go very wrong. It's lucky nothing happened but I'm sure she won't see it that way."

Superman actor the late Christopher Reeve was paralysed after falling from a horse in 1995 during a three-day event in the US.

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