The residents of a remote Hebridean island were surprised by a very special guest in 2006.
But they were even more astonished when the Queen asked if local man, Don Dennis, could act as her chauffeur on the unannounced trip to Gigha to celebrate her 80th birthday.
The Princess Royal acted as an outrider, prior to the arrival of her mother, who paid a private visit to Achamore Gardens, the home of Horlick’s renowned Rhododendron and Camellia Collection.
The revelation is featured in a new series of BBC Countryfile programmes – filmed with special permission from Her Majesty the Queen and the Duke of Edinburgh – at the royal estates at Windsor, Balmoral and Sandringham.
Using a private charter ship, the monarch travelled to the most southerly of the Inner Hebrides.
Princess Anne went ahead on a bicycle to find suitable transport and turned up at one of the local shops, where she bought some groceries.
Mr Dennis said: “The shopkeeper recognised her, but his wife didn’t, so just as the Princess was leaving the store, she shouted: “Hey missus, you’ve forgotten your bananas!”
With no taxis on Gigha, the responsibility for driving the Queen fell on the shoulders of the local dairy farmer.
He added: “I said I’m not too busy, I can do that. I don’t think I had even shaved that morning and I was wearing shorts.
“The Queen was in the front passenger seat and Princess Anne was directly behind her in the back of the car with her husband.
“They went to the gardens. They really are the jewel of the island. It was very special.”
Following that unexpected visit, the Queen travelled on to Jura and Islay.
The Countryfile programme explores her passion for the Highlands and Islands but it also shows footage of her taking her children into an ice cream shop in Ballater and preparing a barbecue in the outdoors at Balmoral, with the Queen laying the plates on the table and her husband preparing the food.
There is also the story of a bothy visitor to the estate, who received some exalted company when he least expected it three years ago.
Geoff Allan said: “In 2015, I came up on a quiet Monday night at the end of August and suddenly, two security guys knocked on the door and they were basically just checking things out.
“Half an hour later, Prince Philip turned up and he was on the barbecue.
“Then, around half an hour after that, the Queen drove herself up to the bothy as well and the couple were clearly enjoying themselves. It was a once-in-a-lifetime encounter.”
The documentary, which will be screened on Sunday June 3 on BBC1, also highlights the Queen’s love of horses and the little rugged Highland ponies which live around the Balmoral estate.
Sylvia Ormiston, the stud manager, said: “Her Majesty is passionate about her ponies and no decision is taken without her.
“Whenever there is a new birth, she wants to know about it, and she loves to hear how the animals are doing.”
The Queen’s own words about her love for Balmoral bring the programme to an end.
She says: “All the children like it, all the grandchildren like it and they sense the freedom there. You can go out for miles and never see anybody and there are endless possibilities.
“We like picnics and we like the open air. The holidays are very short, so you live it to the full.”
The first programme in the series – about Royal Windsor – will be shown on Sunday May 27.