The only topic any self-resecting columnist connected into the political zeitgeist and worth their honorarium should be writing about this week is the last days of the Ardern premiership, and the political ramifications that flow from her decision to pull an Evita and leave us all wanting more.

However, as regular readers will by now understand, I am not the above named columnist, and in any event I am well through this week’s column and cannot bring myself to add my voice to the googleplex of pixels that has been devoted to the hyperventilating speculation by pundits who did not see this coming (and, as a consequence, their reckons on why it did happen can and should be ignored).

Instead, I want to look backwards to where it all began. To God’s first lament, when he cried to Cain: “Where is Abel, thy brother?” To which Cain, rather caustically, replied: “Am I my brother’s keeper?”

For those not familiar with the story, this is the King James biblical telling of mankind’s first homicide; the murder of Abel by his elder brother Cain.

Cain was, we are told, unhappy that God favoured the offerings of his younger sibling, which seems a thin justification for an extra-judicial killing, especially when humanity, at that juncture, held just four people.

The foundation myth of the West rests on an act of fratricide, as does that of the eternal city, Rome. Romulus and Remus, the brothers suckled by a she-wolf, as adults squabbled over which hill to found the eternal city on; and in one telling of this story, Romulus murdered his twin.

There is something darkly fascinating about a fraternal blood feud.

Shakespeare’s Hamlet is based on the murder of King Hamlet by his brother Claudius and the struggle for justice by the young king’s son.

His play Richard III is based on a real king, the maligned Yorkist usurper who, it is alleged, murdered his two nephews to seize the throne.

Richard was the younger brother of King Edward IV, himself a usurper, who can count as one of his achievements the murder of younger brother George by having him drowned in a barrel of wine.

George was the Prince Harry of his day, always complaining about a lack of serious responsibility and whining from abroad.

Infamous as Richard III is, no act of rebellion can trump that of John, younger brother to Richard the Lionheart, who raised rebellion against his brother by forging an alliance with the French while his brother was off attempting to recover Jerusalem and murdering hostages in Acre.

John, who is best known for being the villain in the Robin Hood saga and the reluctant grantor of the Magna Carta, is one of a long list of sniping royal spares. He was fortunate in that he succeeded in stumbling into the Crown, but most have not fared as well.

A rare exception was Prince Albert, younger brother to the troubled Edward VIII. Edward came to the throne in 1936 after a playboy existence and, given the choice between remaining monarch and marrying an American divorcee, chose the latter and Albert ascended to become George VI.

The saga of Prince Andrew and the delightfully self-destructive lifestyle of Princess Margaret are often referenced when commentators feel the need to place the drama of Prince Harry into a historical context, but this is to misdiagnose the issue and our fascination with it.

Neither Andrew nor Margaret fell out with their families. At least, that was not the cause of their problems. They encountered troubles, heartache and, in the case of Andrew, some ugly litigation as a consequence of his association with Jeffrey Epstein.

The conflict between Harry Windsor and his family is a much darker and more complex affair.

We are fascinated with the feud between the Duke of Sussex and his brother. The cultural taboo Harry is breaking in attacking his brother and the hint of an Oedipus complex is the re-telling of an ancient story in a post-modern setting.

Harry’s book Spare is a massive publishing success. Whether it belongs in the fiction or non-fiction section is something later writers can squabble over, but the popularity of this tale can be measured in the clear-felling of rainforests in order to keep the paper mills running.

Equally entertaining has been watching the likes of Piers Morgan implode in a self-administered orgy of bile directed towards the Duchess of Sussex. Morgan simply has no sense of history nor any ability to sit back and enjoy the pantomime for what it is.

And let us not overlook our own part in this production. The Netflix documentary, Oprah interview and now Spare. We, the public, are playing our part as willing and enthusiastic consumers of this melodrama.

Harry and Meghan are selling their stories because we want to buy them, and few tales are more compelling than two brothers tearing each other apart in the full gaze of the media and a gleeful public.

The former King Edward VIII lived a flimsy post-royal existence and died in relative poverty. The lesser members of the wider royal family appear to live comfortable but not especially lavish lives.

The commercial success of the Sussexes’ antics are going to be substantial, and their wealth is driven by our desire to buy what they are selling.

We are a mere 70 generations away from the Coliseum, and we are all the descendants of Cain.