Picture Leonardo da Vinci as a 42-year-old artist, struggling with ideas in his head and a world that won’t allow him to bring them to fruition. Ross King planted that picture firmly in this critic’s head, before slowly creating an arresting image of his own — of how one of the world’s most famous paintings was born, thrived, painted over and eventually restored to glory.

It’s an astonishing story, not least because it demolishes tin-pot theories floating around the painting that made a certain writer of thrillers an enormous amount of money. The good thing Dan Brown did, in retrospect, is draw a lot more attention to The Last Supper, probably prompting people like Ross King to look at it anew. If that is indeed the case, Brown deserves a Thank You note.