In fact, Sophie, Prince Edward and their two children Lady Louise Windsor, 16, and James, Viscount Severn, 12, were the first royals to visit the Queen and Prince Philip in Balmoral.
The Scottish royal residence is where the Queen, 94, and Prince Philip, 99, are spending the end of their summer – and usually enjoy several royal visits there each year.
However, due to coronavirus any visiting royals will have to socially distance themselves from the monarch.
Sophie, Countess of Wessex, 55, and Prince Edward, 56 were seen walking around the grounds of Balmoral with their two children and the Queen in early August.
Read More: Sophie Wessex and Edward’s Balmoral trip may have been strategic
The friend revealed to the publication: “This fascination with military history is a key to the pair’s closeness.
“They’ve watched countless films together and at weekends the pair are sometimes gone for hours, poring over documents in the Royal Archives, which are kept at Windsor Castle.
“Sophie is hugely well read on her military history, she’s proud of her knowledge of military campaigns, and she and the Queen can chunter on for hours about whether this general or that admiral made the right move in some battle or other.
“If Philip is around he just raises his eyebrows and goes into another room.”
Another reason the two royal ladies may enjoy a close relationship is due to the Queen’s view of Sophie as unproblematic and dedicated to her marriage.
A senior royal aide told the Sun: “The Queen is also mindful that Sophie’s marriage has survived where her other children’s relationships have failed – and she knows that is in no small way down to Sophie’s dedication – she is aware, as his Edward’s mother, what a tricky creature he can be.
“And not only has Sophie flourished as a dedicated, albeit still relatively junior member of the Royal family, she has brought up two teenagers who are well-balanced, sporty, amusing and delightful.”
Three of the Queen’s four children have gone through divorces in previous years.
Princess Anne divorced Captain Mark Phillips in 1992, Prince Charles and Princess Diana separated in 1992 before divorcing in 1996 and Prince Andrew and Sarah Ferguson also divorced in 1996.
