The National:

WHAT exactly are Royal visits for? The answer - at some level - is always political. Unless, like Daily Mail columnist Sarah Vine (aka Mrs Michael Gove) you think that the Cambridges turning up in the devolved nations this week was all about royal “moral-boosting” in a time of plague.

For the record: the government of the day always approves any major royal activity. Or did you think (like our Sarah) that the William and Kate just happened to turn up in Scotland, Wales and the North of England when Boris was flag waving over the new vaccine and rushing to Brussels to put those pesky Europeans in their place.

‘Twas always thus.

Back in 1822, Sir Walter Scott was recruited to stage-manage the royal visit to Edinburgh of George IV. The Napoleonic Wars had ended in mass unemployment, triggering popular revolt by the new working class. In 1820, the Radical War in Scotland was countered by mass arrests, show trials, deportations and executions.

The Cabinet decided to send George IV northwards on a propaganda mission to placate the jumpy landed aristocracy and slave-owning middle classes, while trying to beguile the underclass into believing its interests were being looked after by the king and his ministers back in London.

Memorably, Walter Scott laid on a nostalgia fest celebrating a Highland Scotland that never existed except in his own fertile imagination. A grumpy King George got into the swing of things by ordering a kilt and accoutrements costing (in today’s money) over £120,000. Balls, pageants and plays were held on a lavish scale and 3000 volunteer cavalry paraded on Portobello beach.

READ MORE: Ruth Wishart: Unionists fume as Nicola Sturgeon fails to curtsey deep enough

Everybody had a good time except the poor bloody Highlanders, who went on being cleared from their ancestral lands for another 40 years.

Indeed, one might argue that the key mission of the modern royal family is to fly the flag. The job was invented by playboy Edward VIII while passing time as Prince of Wales. Edward visited most of the then Empire, including the wretched, depressed coalfields of inter-war Britain.

To give him his due, Edward was shocked by the mass unemployment he found there, which made him politically unreliable thereafter. However, a close brush with reality did nothing for Edward's racism towards the rest of the Empire. He wrote to his mistress, Freda Dudley Ward, that the Australian aboriginal people were “the most revolting form of living creatures I've ever seen!!”

I’m sure the photogenic Cambridges do not share the racism of Edward VIII or the lascivious lifestyle of the reactionary George IV. But I would not go so far as Sarah Vine in calling them “twinkly ambassadors” or “a masterclass in how royalty can remain relevant in the modern age”. Their job, as with all their unelected predecessors, is to divert attention in times of political, economic and social distress.

Ms Vine deludes herself into thinking a quick visit by the third in line to the throne and his wife will transform Unionist fortunes in Scotland. Rather typically, and with supreme irony, Vine used her vacuous Daily Mail column not to promote national unity or give genuine thanks to the underpaid staff of the NHS. Instead, she happily battened on to the Cambridges in order to attack Nicola Sturgeon (“grumpy”) and Welsh Health Minister Vaughan Gething (“disobliging”).

Vine ends her political diatribe by forecasting that “the long-term future of the monarchy is in safe hands”. But she gives herself away a few paragraphs earlier when she contrasts the squeaky clean Cambridges to the obnoxious Prince Andrew and the runaway Prince Harry.

Ms Vine’s real purpose is to promote the Cambridges as heirs to the Windsor “family firm”, because the track record of most of the rest of the bunch is dubious to say the least. But that’s the problem you get with an hereditary, unelected head of state.

As it happens, the SNP is still committed to retaining the Windsors as head of state, post-independence. After all, they already have a couple of big houses up here, so we won’t have to fork out for an official residence.