Is there really a 'Balmoral test' which royal girlfriends and politicians have to pass?

Watch: Emma Corrin on pressures of playing Princess Diana in The Crown

The Crown season four is bringing a new character to our screens as Princess Diana finally enters the royal fold.

From introduction to Charles to their wedding and royal life, the show will paint an intimate picture of the princess and her life in the palace.

But one of the first things it will show Diana doing is facing the so-called ‘Balmoral test’.

In episode two, Diana finds herself invited to Balmoral, the Queen’s Scottish country estate, for a few days to see how she might fit in with the rest of the royals.

Of aristocratic stock, Diana is able to rise to the challenge, handling anything that comes her way, all with a twinkle in her eye.

The Crown will depict the ease with which she settled into royal life against the difficulty Margaret Thatcher faced when she first went up to Balmoral.

But is there really a test? And did Diana really pass?

The Balmoral Test

According to A Brief History of the Private Life of Elizabeth II, written by Michael Paterson, there is a ‘Balmoral test’.

He said it was easily passed by the Queen Mother, when she was dating the future King George VI, and by Prince Philip.

He wrote: “It has been speculated that there is what is called ‘the Balmoral test’. Any prospective spouse who fails to enjoy the spartan surroundings, or the tiring days spent tramping the hills in the rain, will not do.

“One who immediately passed this had been Elizabeth Bowes-Lyon, while a conspicuous failure was her sister-in-law, Wallis Simpson (on first glimpsing the tartan carpets, she had exclaimed: ‘Those will have to go!’).”

Other royal commentators give a similar story of the ‘Balmoral test’. The Royal Family is understood to be most at ease in the Scottish retreat.

Former royal butler Grant Harrold said of guests of Balmoral: “You are going to be out on the hills with the Queen or other members of the Royal Family, perhaps fishing, hunting or doing other country pursuits.

“Balmoral is a great place to be around the Royal Family and for them to get to know you.

“It can be a bit of a test to make sure you pass the muster.

“You are going to want to dress the part, speak the part and behave the part.”

Princess Diana at Balmoral

Diana’s invitation to Balmoral brings some confusion to the Queen, who asks Anne if Diana is a friend or a girlfriend.

Anne tells her mother that working that out is precisely why Diana has been invited.

Emma Corrin, who plays Diana in season four, said of the Balmoral episode: “When you are invited to Balmoral, it's ultimately a test. Balmoral is where the Royal Family are most at home and so if you are invited you know that is make or break.

“Diana knew that because she already knew how these things work and I think she, although she was incredibly young and so in a way, naive, I think she also very much knew what she was doing. She knew the rules.

“She knew why she was here - to be approved - and I think she just turned on the charm. Philip in particular really loved her so she was given the seal of approval - he talked to Charles and said she's the one what are you waiting for.”

Diana made her first trip to Balmoral in September 1980, and she’s snapped there by paparazzi, meaning the end to the secrecy of their relationship.

Harrold said: “For Princess Diana, that was easy. She came from a similar background but that’s not true of all the guests who are invited to Balmoral.

“It can be terrifying for anyone to spend a few days with the people who are going to be your in-laws regardless of who they are, let alone one of them being the Queen.”

While Diana passed the test, she came to hate Balmoral.

According to the biography Diana: In Her Own Words, she said: “I panic a lot when I go up to Balmoral. It’s my worst time, and I think: ‘How the hell am I going to get out of this?’ The first couple of days I’m frightfully chirpy when I get up there and everything’s wonderful.

“By the third day they’re sapping me again. There are so many negative atmospheres. That house sucks one dry.”

Commentator Richard Fitzwilliams said: “The Balmoral ‘test’ was initially passed by Diana who was later unhappy and bored there.”

Did Diana really kill a stag?

The episode of The Crown includes family members concern about an injured stag which has wandered onto crown land. Anne and Philip are competing to kill it.

Diana joins her father-in-law to be on a stalk and is the one who spots the wounded animal which allows Philip to take it out.

It’s not clear if such an event really happened, but the Royal Family does hunt when they are up in Balmoral.

According to reports from 1981, Diana found herself in the bad books of the League Against Cruel Sports for taking part in a shoot when she was there for her honeymoon.

The LACS said she “shot and wounded a deer” and it had to be stalked a considerable distance and shot by a marksman.

However the palace fired back: “We are not denying or confirming that the princess took a shot at any deer. What we are stating as being untrue is the incident described by the League Against Cruel Sports.”

Margaret Thatcher at Balmoral

It’s tradition for prime ministers to be invited up to Balmoral for some time in August, and The Crown will explore Thatcher’s relationship with the Queen in part in how they got on when in Scotland.

Watch: Who is Margaret Thatcher?

According to the biographer Ben Bimlott, Thatcher regarded the weekends at Balmoral “like purgatory”.

She managed to upset the Queen by interrupting her doing the washing up according to Charles Moore, author of Margaret Thatcher: The Authorised Biography.

He said: “The Queen loves washing up on these occasions. So it’s all completely unlike being at the palace.

“But Mrs Thatcher found this very difficult. She couldn’t bear the idea of watching her sovereign washing up while she’s sitting down and doing nothing. So she would like to get up and help with the washing up.

“The Queen used to find this quite annoying, because it was taking away her special treat.”

She’s also said to have frequently arrived with unsuitable footwear for the various walking, fishing and hunting trips she would have been invited on and had to borrow Wellington boots.

And the workaholic, who used to sleep just a few hours each night, would leave promptly on her last day to avoid one last breakfast with the family.

But it appears the trips did help to soften their relationship in some ways. Thatcher sent the Queen a pair of washing up gloves after spotting her doing the dishes without any one year.

The Crown is streaming on Netflix from 15 November.