When showing visitors around London I would often get asked: Have you met the Queen? As I have done nothing in my life that would warrant a royal introduction I am always taken aback by the question.

But it’s fair to say that I have often ‘seen’ the royals while guiding in London. Usually, it’s a glimpse of someone behind a car window. Occasionally, like on this video, I spot an excited crowd, sneak through to a convenient position, pass the scrutiny of the private detectives and get a glimpse – in the distance – of the King himself. I experienced a frisson of excitement.