There are three things that reliably happen every August: bank holiday travel chaos; scorching temperatures in the Med; and the great Scottish migration of the royal family — an event similar in scale to that of the wildebeest in the Serengeti, but with fewer crocodiles.

Things have been bubbling under on the tartan front for a couple of weeks now, with the King and Queen making brief raids north of the border. There’s been a church service here, a heritage centre to open there: the bread and butter of royal life. On Monday, however, the migration went Instagram Official at the gates of Balmoral, where the King, wearing a kilt, inspected a guard of honour and a Shetland pony. Last week Prince Andrew arrived; this week it’s the prime minister. Any day now it’ll be the Prince and Princess of Wales. Let the Highland games begin.

The royals can, and do, travel anywhere in the world. For better, for worse, they always go back to Balmoral where, surrounded by hills and cut off from the world, they have 50,000 acres, the size of a small city, in which to shoot things in privacy.

King Charles at Balmoral Castle with a regimental mascot pony and soldiers.

King Charles at the gates of Balmoral Castle this week

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Balmoral Castle exhibits on private tour.

The castle’s entrance hall

VISITOR ENTERPRISE FOR BALMORAL CASTLE

The estate was bought by Prince Albert for Queen Victoria in 1848; she loved its remoteness, finding it a place “to breathe freedom and peace and to make one forget the world and its sad turmoils”. After another year of torrid headlines, Andrew, ensconced with his ex-wife, Sarah Ferguson, in a seven-bedroom lodge on the estate, may reflect that little has changed since then. Apart from Christmas at Sandringham in Norfolk, summer at Balmoral is the only time the whole royal family gathers together. Alas for Andrew, he was NFI to Norfolk and it was turkey for two for him and Fergie at Christmas, after his association with an alleged Chinese spy was exposed. That the King has invited him now may be a show of support, or a reflection of the fact the King is fond of his nieces, Beatrice and Eugenie.

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It’s no coincidence that he’s been billeted under a different roof from Prince William, who is hyper-aware of the reputational damage Andrew is apparently endlessly capable of inflicting. Traditionally Balmoral has been the place where the royals can be most “themselves”. A new book portrays Andrew as the sex-mad useful idiot for a paedophile, so William and the King may perhaps pray that he doesn’t lean into that tradition too much.

Back in the day, Balmoral was where Prince Philip was “master of the barbecue”, as Prince Harry put it, paying tribute to his grandfather after his death. Queen Elizabeth marked his passing with a photograph (taken by Sophie, Duchess of Edinburgh) of her relaxing with Prince Philip on the hills around the castle.

Prince Philip and Princess Anne barbecuing at Balmoral Castle.

The Duke of Edinburgh and Princess Anne on the estate in 1972

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It was to Balmoral that Lady Diana Spencer was sent to be “vetted” before her marriage — a test she passed with flying colours. It was from Balmoral that Fergie was banished, after the repose of the royal breakfast table was ruined by front-page pictures of her toes being sucked.

The castle is well stocked with wellies, walking sticks, fishing rods and waterproofs, its heavy wooden front door invariably propped open with a curling stone and attended by a footman in a scarlet uniform. Dogs and children run wild. The interiors are a carpeted riot of flock wallpaper, tartan curtains, ornaments, stags’ heads and oil paintings, creating an effect much as Laurence Llewelyn-Bowen might design after too many Tunnock’s teacakes. And while Keir Starmer may view his invitation as an honour or an ordeal, he will at least be spared having to join in with “kick the can”, a royal form of hide and seek that prime ministers were required to play when the King was a boy.

“Nothing has the same meaning and soul-refreshing quality that Balmoral has,” the King wrote more than 50 years ago of the place described by one of his biographers as “the closest approximation to a normal family life that he could conceivably experience. This was the home where he played ping-pong and football … or cycled to the village shop.”

Prince Andrew and Sarah Ferguson arriving in Scotland.

Prince Andrew and Sarah, Duchess of York, in 1986

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His first engagements as King were in Scotland and since then he’s established his own tradition of spending three weeks a year at the castle, preceded by a short stay at the Castle of Mey and followed by a longer sojourn at Birkhall, his own home eight miles from Balmoral. His first instruction on arriving at Balmoral as King was to open the windows; he has also ordered a rehang of the pictures, a refresh of the tartan drapes and the creation of a thistle-shaped maze.

“His habit during these visits has been to spend his mornings reading documents and to set aside some afternoons for fishing,” says his biographer Sally Bedell Smith, noting that he also enjoys driving himself around and stopping to chat to farmers.

According to a former adviser to Queen Elizabeth, the King’s love for Scotland is also tied up with concern for the future of the United Kingdom. “It’s not just about shortbread, pipers and kilts, and the family need to reflect that,” the adviser told the journalist Robert Hardman.

Prince Charles and Princess Diana on their honeymoon at Balmoral Castle.

Charles and Diana, Princess of Wales, on their honeymoon in 1981

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William has not always seen eye to eye with his father, but on Scotland they agree. Having started their summer holidays this year on a yacht in Greece, the Wales family will end them, as is tradition, in Scotland. “My childhood was full of holidays having fun in the fresh air, swimming in lochs, family barbecues with my grandfather in command — and yes, the odd midge,” he has said, adding that “a big part” of him would always be in Scotland.

While his mother hated the place, his wife loves it and his grandmother bequeathed him his own home on the estate, a three-bedroom cottage called Tam-Na-Ghar on the banks of the River Muick, not far from Birkhall, where the couple retreated for complete privacy during the early days of their romance, when they were students at St Andrews. It was to Scotland that William invited Kate’s parents when he wanted permission to marry her, borrowing the much larger Birkhall from his father for the occasion. Formalities complete, his future in-laws were photographed being taught how to stalk deer.

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“George, Charlotte and Louis already know how dear Scotland is to both of us,” William has said, “and they’re starting to build their own happy memories here too.” Both George and Louis have been seen on shoots at the estate.

As for their errant uncle, Harry’s memoir, Spare, begins at Balmoral with the brothers’ annual two-week stay. Harry was happy there, he writes, fishing, shooting and running around with his brother; he describes it as “simply a paradise, a cross between Disneyworld and some sacred druid grove”.

Prince Charles, Prince William, and Prince Harry at Balmoral.

Charles with Prince William and Prince Harry in 1997

TIM GRAHAM PHOTO LIBRARY VIA GETTY IMAGES

Nevertheless, while his children have been to Disneyworld, they have not been to Balmoral, which by 2019 had evidently lost its charm. Harry and Meghan turned down Queen Elizabeth’s invitation to journey north with baby Archie in favour of crisscrossing Europe on private jets.

In an uncanny coincidence, William and Kate were photographed that year with their children catching a budget flight to Aberdeen. Soon they’ll be heading north again to play happy families in the Highlands. It’s a fair bet that whoever is master of the barbecue these days, it won’t be Andrew.