Whatever the Prince of Wales’s reaction to his brother Harry’s revelations in his memoir Spare, it’s doubtful that he’s dwelling right now in the land of Nod. Indeed he may well be enduring some sleepless nights following the disclosure that he knocked his younger brother to the floor during a heated confrontation in 2019.

In biblical terms, of course, the land of Nod is not a state of unconsciousness but the place where Cain was condemned to live after he had killed his younger brother, Abel. That story of fraternal frictions and jealousies is one of the founding myths that has informed the Abrahamic religions and our understanding of the hatred that can accompany brotherly love.

It speaks of something impassioned and primal, a powerful force that is immune to reason, which certainly corresponds to the scene that the Duke of Sussex describes when William came to visit him at Nottingham Cottage.

Apparently, the older brother wanted to discuss “the whole rolling catastrophe” of their relationship. But as is often the way with such a baggy agenda, little progress was made, and Harry ended up on his backside picking pieces of broken dog bowl out of his flesh.

If that lively kind of fraternal interaction will be familiar to many households, it’s also true to say that in most cases brothers grow out of it by the time they are old enough to vote. However, William is 40, Harry is 38, and they are currently on course to rival the Gallagher brothers, Noel and Liam, in…