A hapless group of tourists once bumped into the Queen walking around her Balmoral estate - but didn't recognise her.
The monarch was out for a low-key walk in tweeds and a headscarf, something she likes to do when she gets the chance.
One of her former protection officers has revealed the 93-year-old likes to slip under the radar when possible.
Richard Griffin claims that once a group of American tourists failed to recognise her.
Speaking to The Times , Richard said the Queen didn't want to blow her cover at the time.
She went along with the tourists as they questioned whether she lived in the area, replying that she had a house nearby.
When they asked her if she'd ever met the Queen, all she said was "No, but this policeman has," gesturing towards Mr Griffin.
Richard - who worked closely with the monarch for more than 30 years - said the group then moved on, having no idea who they'd just met.
During her trips to Balmoral in Aberdeenshire, Scotland, the Queen famously enjoys a low-profile lifestyle.
She chooses to wear pared-back clothes and wellies, as opposed to the brightly-coloured outfits she's known for.
According to biographer Robert Hardman, Her Majesty purposefully dresses in eye-catching shades during royal engagements.
In his 2011 biography Our Queen, the author described her as "engagingly modest".
He wrote: "My favourite remark she ever said was: 'I can't ever wear beige because nobody will know who I am.'"
