Phillips paraded with Toytown at the Burghley Horse Trials

"Back in the spring, things were going badly, I was riding badly and I thought about giving up, I was so depressed," she said at the Burghley Horse Trials.

"Then I went on holiday and took advice from Pippa Funnell. She motivated me and told me to do something different.

"Eventually, things got better and I was able to focus on the World Games."

Among a run of disappointing form was a day at Belton Horse Trials in early April where Phillips took three horses.

She fell from Ardfield Magic Star, finished with a heavy score of 129 penalties on Red Baron and made five showjumping mistakes with Toytown.

My grandmother was watching on interactive television, and she rang me to say 'well done' Phillips reveals how the Queen enjoyed her success

But a pep talk from Olympic-medallist Funnell had the desired effect despite Phillips then suffering a bereavement when her great friend, Irish rider Sherelle Duke, was killed in a freak fall at a horse trials in Hampshire.

"It was a massive shock," admitted Phillips, "Sherelle was a very special person. The other riders were immensely supportive.

"I felt Sherelle was up there urging me to go on and do my best. I owed it to her."

The 25-year-old went on to add the world title to her European crown last month on Toytown.

"I haven't really come down to earth since winning at the World Games," she added

Phillips revealed at the end of the showjumping in Aachen, it took her a few moments to realise she had won, though grandmother, the Queen, was quicker off the mark.

"My grandmother was watching on interactive television, and she rang me to say 'well done'," she said.

She also paid tribute to the support she received from her partner, England rugby centre Mike Tindall.

"He gave me a lot of confidence and was a major support," she said.