She's one of the hardest working royals often quietly travelling up and down the country to carry out her duties.
And at the side of Princess Anne during many of her countless royal engagments is her quiet yet supportive husband Vice Admiral Sir Timothy Laurence.
The pair got married on this day exactly 30 years ago on December 12, 1992, in a small, private ceremony in Balmoral.
But despite their long marriage, Sir Tim appears to keep out of the limelight and is a non-working member of the family with no title. Here's what we know about him and his royal marriage to Anne...
Early days
Sir Tim was born in Camberwell, London, in March 1955, making him five years younger than his wife.
He attended Durham University, where he was the editor of the famous student newspaper Palatinate and gained a degree in geography.
After graduating, he attended the Royal Naval College Dartmouth and enjoyed an illustrious naval career serving on several ships, including the Royal Yacht Britannia and rising to the rank of commander.
In 1986 he was appointed an equerry to the Queen - a personal assistant, who is usually derived from the armed forces - and it is during this time he is said to have met his future wife.
Stolen letters
The first whispers of a closeness between Sir Tim and Anne - who was still married to first husband Captain Mark Phillips at the time - came in 1989 when personal letters were stolen.
A newspaper then reported on the existence of these letters but did not reveal who Anne had received them from.
Buckingham Palace later revealed they were from Sir Tim and issued a statement saying: "The stolen letters were addressed to the Princess Royal by Commander Timothy Laurence, the Queen's Equerry.
"We have nothing to say about the contents of personal letters sent to Her Royal Highness by a friend which were stolen and which are the subject of a police investigation."
Balmoral wedding
In 1992, once Anne's divorce from her first husband was finalised, she was then free to marry to Sir Tim.
Their wedding took place at Crathie Kirk near Balmoral Castle in a service that was attended by roughly 30 guests, including the Queen and Prince Philip as well as Anne's children Zara Tindall and Peter Phillips.
Instead of a traditional wedding gown, Anne wore a high neck white midi dress with a matching jacket, carried a posy of heather and wore a sprig of flowers in her hair.
The couple then settled and still live together on the Gatcombe estate in Gloucestershire close to both Peter as well as Zara and her husband I'm A Celeb contestant Mike Tindall.
Special privilege
Despite his low-profile nature, it seems Sir Tim holds a special place in the royal family, with the late Queen seemingly fond of him.
Although he didn't receive a royal title upon marriage, he has since been made a Knight Commander of the Royal Victorian Order and was also a personal aide-de-camp to the Queen.
Earlier this year at the time of her Platinum Jubilee celebrations, he was given special permission to join the monarch on the Buckingham Palace balcony after Trooping the Colour .
It had previously been announced that the Queen would only allow working royals to join her for the flypast, but made a special exception for Sir Tim, two of her grandchildren and three of her great-grandchildren.
A Palace spokesman explained the decision and said: “In addition the Cambridge and Wessex children, also expected to appear as is Sir Tim Laurence, who the Queen is happy to attend as a frequent attendee and support for the Princess Royal on official engagements.”
'Invisible support'
And it is on these royal engagements where Sir Tim offers his support with some even describing him as "invisible".
However, much like the late Queen, he is well-known for his good sense of humour and had crowds in stitches when he stood in for Anne at Founder's Day at The Royal Hospital Chelsea earlier this year.
Giving the speech, he joked: "Asking me to stand in for my wife at an event like this is a bit like asking Mrs Harry Kane to lead the England football team out.
"Or, possibly, to take a penalty for England as her husband did the night before last. I don't know Mrs Kane, and for all I know she may well have a very strong right foot, but in any case I'm sure she'd do her best, and so will I."
He retired from the navy in 2010 and is now the chairman of the English Heritage Trust and was the former vice chairman of the Commonwealth War Graves Commission.
However, no doubt the time when most support was needed for his wife was after the death of her beloved mother the Queen earlier this year.
Sir Tim accompanied Anne as she joined her mother's coffin for its six hour long drive from Balmoral, where she died, and through the breathtaking Scottish countryside to Edinburgh, where she rested before being take to London.
He joined his wife again as the coffin was brought to London on an RAF flight from north of the border and was there in solidarity walking behind the monarch's coffin during her funeral.
