Zara Phillips is the world’s greatest tightrope walker. Over the past four days, she has been walking at least three. For once she has passed only two of them with distinction, the last of three she leaves with only credit: an unaccustomed beta-plus.

She is no longer European eventing champion. Even without the catastrophic stop by Toytown in the showjumping yesterday, the superb Nicolas Touzaint, of France, would have won. All the same, Phillips has been a crucial part of Great Britain’s victory in the team event that runs side by side.

The three tightropes of the weekend are second nature to her.

The first is the essential contradiction of eventing: to train a horse that is fast and bold over the cross country, but still has the coolness for dressage and showjumping. Phillips’s dressage put her into second place, her cross-country round, dashing and clear, kept her there.

But after an awful and absolutely baffling stop in yesterday’s showjumping, she acquired 19 penalties and sank to sixth. She was a picture of gloom afterwards. It was a stop that asks dreadful questions about Toytown, the horse which she will now – after achieving qualification this weekend – ride at the Olympic Games next year.

The second tightrope stretches between the desire for individual glory and the duty to work for corporate triumph. A royal must work for shared goals, a princess’s daughter has to do her bit for the people. Team first – that has always been the way.

So Phillips rode her cross-country round under team orders, taking the longer routes where instructed. She responded with a heart-on-sleeve performance, her rangy chestnut horse fast and brave, his impetuous nature brilliantly managed. This was a great rider on top of her game and no one could help but thrill to the sight, whether her grandmother was a washerwoman or a Queen.

Until afterwards, of course. That was when the the third and most perilous tightrope manifested itself. After the equestrian press had discussed overreach boots and team orders, a writer from a local publication – not, I suspect, equestrian-based – asked if her mother was pleased. You needed Jedi reflexes to catch the irritation in Phillips’s eyes: a nanosecond later she found a smile and a polite answer. “And what eez eet you find bettair – ’orses or people?”

Now Phillips is a woman who has escaped the tyranny of abstract ideas and at the best of times she finds such questions meaningless. She responded – apparently without a concupiscent thought in her head: “It depends what you’re doing.”

Being a royal, being a serious full-on professional athlete: it’s one of the hardest balancing acts anybody could be asked to perform. In a more circumscribed age, her mother - much nearer, of course, to the throne – never really pulled it off.

But Phillips knows to a hair how to play it: aware that royalty is a huge bonus in terms of publicity, backing, income and ungrudgingly accepting that there is a payback.

In a freer and easier age than her mother knew as an elite competitor, Phillips has the scope and the mentality to be a competitor first, a royal second. She is an emblem, if you like, of a changing society, of the differences in the stars we choose to gaze on. All the same, it is royalty that propels her from stardom to superstardom. She knows this and rides the contradiction with as much élan as she rides Toytown.

But you, dear reader, should never, for one second, miss the essential point. True, a great rider never seems to do anything special. It is a mystery, and it is used to praise all stars of horsey sports, unless they come from a privileged background. Then, it is used to suggest that the horse does all the work, that the royal rider is just a passenger. But this is not the case. Phillips is a wonderful rider who has just had a horrific setback. She will work to eliminate this with all her fearsome talent. The Olympic Games lie ahead and everything in her nature, royal or otherwise, is directed towards the four defining days of her life in China next summer.

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