Kate Middleton has to fix the 'spare' problem not resolved by the Queen. Photo / Getty Images
Opinion:
Get out your good bunting and make space on your commemorative spoon rack (you do have a commemorative spoon rack, right?) because there is a Royal Jubilee in the offing!
Next year will mark 70 years since Queen Elizabeth ascended to the throne and thus it's time for a good deal of Union Jack flag-waving and cream tea-consumption in the form of her Platinum Jubilee.
In 1977, for her Silver Jubilee she got the rare opportunity to go for a spin on closed London streets in the actually gold-covered Gold State Coach.
In 2012 for her Golden Jubilee, Her Majesty got a new $1.7 million Royal Barge and the chance to float down the Thames on a drizzly morning surrounded by her family.
And in 2022? There will be a four-day holiday weekend, enough pageantry to make even the most ardent monarchist feel a bit sick.
Despite the Queen's seven decades on the throne, she's still plagued by an age-old, royal dilemma. That is: The Riddle Of The Spare.
Since William the Conqueror got into his head to cross the Channel, being the monarch has necessitated not only the production of an heir but also a spare, lest the first one manages to lose his head at Agincourt or their sybaritic princely lifestyle catches up with them. (Agonising gout anyone?)
The spare was the understudy, perpetually kept in the wings in case the worst happened – in case dynastic destiny or a bloodthirsty traitorous Baron caught up with them.
(And yes, they were mostly blokes – in Britain's 1000-plus year history of monarchs, there have only ever been eight queens regnant, that is a Queen who rules in her own right, including Elizabeth II.)
It perhaps comes as no surprise there is a long and slightly miserable history of second born royal sprogs being about as wretched, bored and resentful as you might expect.
From George, Duke of Clarence, younger sibling to both King Edward IV and King Richard III, whose penchant for plotting against his brothers saw him executed, to the chain-smoking Princess Margaret whose greatest contribution to the historical record were her epicly haughty put downs.
When the 21st century came around, the Riddle of the Spare became only more pressing.
In 2001, Prince Andrew left the Navy after a distinguished 20-year career to do … something. Without any definable role waiting for him he landed a gig as the British government's special trade representative, a position that repeatedly landed him in hot water over the next decade.
(The less said about that time he invited the son-in-law of an African dictator for lunch at Buckingham Palace or the dinners he shared with former Libyan tyrant Colonel Gaddafi the better.)
And then we get to Prince Harry, a man who despite his hunger to do good, intrinsic ability to connect with the masses and significant natural talents, the palace still couldn't work out what to do with him.
Things were outwardly fine when the red-headed royal was (seemingly) content to play cheeky third wheel to his brother Prince William and his wife Kate, Duchess of Cambridge. Off the threesome would go, a giggling trifecta of HRH-dom.
However, things got far more complicated when Team Sussex was born with the addition of a smart, educated and accomplished woman to their ranks in the form of Meghan Markle. Suddenly the Sussex duo was eclipsing their staid Cambridge counterparts in terms of media coverage and in the public adoration stakes.
A series of biographies which came out last year have argued that the chasm between the treatment Harry and Meghan received outside versus inside palace walls ultimately contributed to their decision to waltz off into the West Coast sunset to make podcasts and snap up greige sofas.
As the spare and thus forced, reportedly, to let his father and brother take precedence despite being the best thing that has happened to the house of Windsor since they stopped marrying their cousins, it is understandable that Harry might have started to chafe at the situation.
And this is where Kate comes in because not only is she the mother of the future king George VII, she is the mother of not one but two "spares" in the adorable tiny forms of Princess Charlotte and Prince Louis.
The clock is ticking down to the day someone has to work out what to do with the Princess and Prince, aside from letting them fester inside Kensington Palace and buy as many polo ponies as they fancy.
For little George, now seven years old, a lifetime of reigning and parliament opening awaits him. He will get to be handy with a sword for the odd-spot of knighting and faces decade upon decade of having to endure weekly audiences with the Prime Minister of the day. To wit, his future is set in perfect Cumbrian stone.
The opposite is true for Charlotte and George. While as children, as it was for William and Harry when they were tiny royal mites, all three of the Cambridge kids are being raised equally, the inherent disparity between George and his siblings will make itself horribly known in the years to come. It is inevitable – sad and inevitable.
What isn't inevitable is what the dickens Kate is going to do about ensuring that her second and third children are not left to flail in adulthood like their predecessors, occupying some strange no man's land in the royal scheme of things. Simultaneously both important in the line of succession and at the same time, absolutely irrelevant unless tragedy intervenes.
While there is a clear-cut path for heirs, which poor old Prince Charles has been on for 52 years now, a prescribed apprenticeship if you will, each spare until now has been left to fumble their way through their careers to very, very limited success. (Charles now holds the record for the oldest person to be next-in-line to the throne since 1714.)
The only second born child to a monarch post Queen Victoria that has in any way made a relatively good go of it is Princess Anne who has approached her nebulous position with a certain stoic resignation and the knowledge she can get back to her beloved horses the minute all the hand-shaking and plaque-unveiling palaver is over.
But the Princess Royal is a serious outlier and a considerable exception if one is to take a gander at the history of the house of Windsor.
The precedent set by spares over the past 120 years is a pretty miserable one. At issue is the inherent disconnect between their upbringing, all of them raised as the children of the King or Queen (or the future King or Queen) with all the pomposity that entails, and the reality of their grown-up lives which is that they are constitutionally irrelevant.
They are defined by, and their lives are inherently limited by, what they are not and that must be a terribly hard place to occupy, child or adult.
Finding a solution to this erstwhile conundrum now falls to Kate and William.
Complicating this situation further is the fact that Charlotte and Louis face a different royal reality to the one Harry stepped into.
When the Wales men began undertaking official engagements they were joining the much larger ranks of working members of the royal family, making them a handy addition but by no means integral to getting the job done.
The reality that the Cambridges face will be markedly different. By the time they are all grown up and ready to charm a rope line, George, Charlotte and Louis will be the only working HRHs under the age of 50.
They will be lumped with the entire responsibility of making the monarchy in any way seem relevant to younger Britons (and whoever is left in the Commonwealth) and with injecting a spot of youthful verve into the whole monarchical endeavour.
Basically, they are going to be needed desperately in the Buckingham Palace salt mines, so to speak, like it or not.