The Princess Royal has topped the league table for Royal duties for many years so it comes as no surprise that she's started this year at full speed. 

The variety matches the quantity. Ranging from being President of the Save the Children Fund to a role as Admiral of the Sea Cadet Corps, nothing seems to ruffle her.

At the start of the year she, accompanied by her husband, Sir Timothy Laurence, Anne visited Sri Lanka where, among her many duties she met the President.

A 19-year-old Princess Anne pictured  in the grounds at Sandringham. She had first undertaken royal duties the year before

Princess Anne with her horse Doublet, after winning the three-day event at Burghley, Lincolnshire in 1971

A proud Queen takes photographs of Anne as she compete in horse trials at Burleigh. Anne became the Three-Day Event Champion on this occasion 

As Prince Philip is said to have once remarked that Anne was the son he had wished to have

When Princess Anne married Mark Phillips, in Westminster Abbey in 1973, she was the first child of a monarch to be wed in a live televised ceremony

Then it was back home to Gatcombe for a training day before leaving for Rosyth in Scotland to watch a new naval frigate, HMS Venturer, being built.

From a Big Curry Lunch as an Honorary Freeman of the City of London to a Commonwealth dinner at Buckingham Palace - followed by another dinner for the Special Boat Services Association at Windsor Castle - it never stops.

And we are still only at the start of the year, with dozens more such appointments lined up.

Anne, the Princess Royal is unique. 

She remains the most enigmatic member of the Royal Family, an aloof and seemingly unemotional woman who has never allowed the ermine cloak of Royalty to fall and expose her real hopes, fears and ambitions. 

She has a devastating wit, a total disregard for the approval of others, and as a former European Three-Day-Event Champion, which she became in 1971 at her first attempt, her physical courage has never been in doubt.

Princess Anne knows exactly who and what she is. Very few men or women are permitted to call her by her Christian name. 

It is always Your Royal Highness at first, thereafter, Ma’am – to rhyme with jam not anything else. 

Anne survived a kidnap attempt by a gunman who shot her bodyguard five times; the scandal of being the first – and only – daughter of a reigning sovereign to be divorced and remarried (to a former servant of her mother), and seen the marriages of two of her brothers, Charles and Andrew, break up in bizarre circumstances. 

She has seen both her nephews, William and Harry, marry and have children. 

And seen Harry and his wife Meghan, the Duke and Duchess of Sussex, desert the Royal Family for the United States, to become ‘independent.’

Not that you will ever hear a word of criticism about any of them from her lips.

When she married her first husband, Mark Phillips, in Westminster Abbey in 1973, she was the monarch’s first child to be wed in a live televised ceremony. 

The wedding to husband number two, Tim Laurence, whom she met when he was serving as a ‘Season Officer’ on board the Royal Yacht, Britannia, was a low key ceremony held at Crathie Parish Church near Balmoral in Scotland, because of the obstacles she would have encountered, as a divorced woman, marrying in church in England. 

And even in Scotland there were difficulties, as Anne did not give the required fifteen days notice for the wedding. So technically she broke the law.

Beginning at the age of 18, when she presented symbolic Leek emblems to the Welsh Guards on St David’s Day, 1970, Anne has continued to pursue her Royal duties with unflagging energy and dedication.

Today, well over seventy, there is little sign of her slowing down. 

She never stops, carrying out up to five different engagements in a day, some of which are stultifyingly boring. 

Though when I mentioned this aspect of her work to her, Anne's reply was a masterpiece in classic, diplomatic understatement.

She merely admitted that: 'Some are perhaps less interesting than the others.'

A workaholic, she hates having a day off. As she told me, ‘I do not like sitting around doing nothing…I try to fill the time.’

In carrying out these duties, she has occasionally been required to show a thick skin – and keep a straight face at some of the remarks she has to listen to. 

I was present in Houston, Texas, at a special dinner, where she was guest of honour and the host stood up to welcome her. He opened his speech by asking the Princess …'To congratulate your mother on being re-elected.' 

She didn’t bat an eyelid.

The years have not been hard on Anne. She doesn’t require the services of a personal trainer to keep her stomach hard and flat, or a hairdresser in constant attendance to keep every strand in place. 

Neither do her hands show any evidence of a weekly visit from a manicurist.

 She has beautiful eyes, a fine complexion and she still wears the same size 10 clothes she wore 20 years ago. She claims that many of her outfits are, indeed, that old.

As the centuries-old Royal traditions of secret protocols, ancient grievances and stifling class distinctions are discarded there is not one word of criticism from the woman who was second-in-line to the throne when her mother became Queen Elizabeth 11 in 1952. 

Today, Anne languishes so far out of sight - as her brothers, nieces and nephews all precede her - that she does not even have to seek the permission of the Sovereign to marry – or divorce. 

It now applies only to the first six. Harry just makes it – for the moment.

Of course, many of the racial, religious and ethnic barriers that surrounded the Royal Family for generations, have tumbled. 

Princess Anne working for Save The Children fund as patron in The Gambia

The Princess Royal seems to be enjoying herself as she accompanies her brother, the King, at last year's Braemar gathering

Princess Anne and Prince William take part in her The Good, The Bad and The Rugby podcast, hosted by her son-in-law Mike Tindall

Princess Anne shares a joke with Kate at a fly-past to mark the centenary of the Royal Air Force  in 2018

Prince Harry and Princess seem helpless with laughter at the Patron's lunch in 2016, part of the three-day celebrations for the late Queen's 90th birthday

She still wears the same size 10 clothes she wore 20 years ago - and claims that many of her outfits are, indeed, that old

They had to in order to bring new blood and vitality into the House of Windsor. 

The days when royalty married royalty have long gone never to return. It’s hard to believe now that in 1960, when Princes Margaret married Antony Armstrong-Jones, (later Lord Snowdon) her aunt, Princess Marina, the widow of the Duke of Kent, was horrified, exclaiming: 'How strange to be marrying a subject'.

A naturally suspicious woman who does not take easily to strangers, Anne has a close circle of friends, most of whom have known her all her life. 

To them she is approachable and loyal, so long as none is foolish enough to confuse friendship with familiarity.

 If one oversteps the mark, the curtain of Royal disapproval descends with chilling finality. 

She may not be a tactile person, yet as a young woman she had the reputation of being a sexy little number, with several boyfriends, including Andrew Parker Bowles, the former husband of Camilla, now our Queen. He has remained one of her  confidants.

Anne believes passionately in the Monarchy and gets extremely angry if it is ridiculed and called outdated. Her view is that it is, and can continue to be, a power for the good of the country - but only if it moves forward.

It is rare for her to lose her temper. The only way one can tell if she is furious, in fact, is when her jaw muscles tighten and her voice becomes a little shrill.

She is not interested in personal popularity and, like her father, the late Duke of Edinburgh, she believes it is not necessary to be liked to be respected, or to become emotional to show compassion.

After a visit to a leper camp, where she didn’t flinch from the most horrific sights, I asked her how it had affected her. 

She replied, ‘I have to be realistic. If every case were treated personally I would go nuts. You have to be remote, otherwise you would crack up.’

Her down-to-earth, no-nonsense approach to her role as President (now Patron) of the Save the Children Fund, the organisation with which she is most closely identified, conceals a natural and inbred haughtiness.

Yet no one could accuse her of the petty vindictiveness or unpredictable behaviour shown at times by her siblings.

She is entirely consistent, and as one of her personal protection officers said, ‘At least you always know where you are with her.’

Her relationship with her parents never wavered. It was a mutual admiration society, based on trust, love and respect. 

Neither could do any wrong in the others’ eyes. I once asked her if she regarded her late mother as Queen first or mother. She said, 'Remember she has been my mother longer than she has been Queen, so that’s how I regard her.'

Anne’s children, Peter and Zara, both born without a title between them, in spite of the pleas of their Royal grandmother to be allowed to make them at least ‘Lord’ and ‘Lady’ have fully justified Anne’s decision. 

They are sensible, well-adjusted adults living comparatively normal lives, with Zara a World Champion equestrian in her own right. 

When she married the former England rugby international, Mike Tindall, Anne welcomed her new son-in-law into the family – and so did the late Queen. Peter Phillips’ marriage to the Canadian Autumn Kelly, ended when they divorced in June 2021. 

Princess Anne made no public comment, though she must have been privately disappointed.

Peter and Zara take in their stride the fact that one of their first cousins, Prince William, will one day be their King.

The Princess Royal is a loving, if undemonstrative, mother and Grandmother who once claimed she did not possess a natural maternal instinct.

However, she has certainly since demonstrated her pride in her children and grandchildren; their mutual affection is plain to see when they are together.

And, after more than 50 years of flawless public service, Anne has become acknowledged as the most respected and admired member of the Royal Family today. 

Princess Anne with Andrew Parker Bowles, former husband of Queen Camilla. He has remained of her closest confidants

When Zara married the former England rugby international, Mike Tindall, left, Anne welcomed her new son-in-law into the family

Princess Anne with her husband, Tim Laurence and her children Zara Tindall and Peter Phillips

For a while, she was thought to be the odd one out - as she put it: 'I’ve always been a tail-end Charlie.' 

Today she is seen as perhaps the woman who is helping to provide the Monarchy with the strength and stability it needs to see it safely into the future.

Or, as Prince Philip is said to have once remarked, she is the son he wishes he had.