“In the end I wanted to take pictures in motion, so with that wonderful wide skirt I made her dance in front of my lens, a kind of accelerated waltz mixed with a pinch of rock ‘n roll,” he said.

In December, the 250 shots were whittled down to 70. The Duchess then picked around ten, before Roversi chose his three favourites.

The “official” one was the one they both preferred, he said, but added that the Duchess was “less sure” than he was about the final choice.

The newspaper suggested that the Duke of Cambridge and their three children, Prince George, eight, Princess Charlotte, six, and Prince Louis, three, chose the “official” sepia image as their favourite.

The pictures will enter the permanent collection at the National Portrait Gallery, of which the Duchess is patron.