Being head of state was a full-time job and left the Queen as a young mother with too little time for her children.

Nannies were called upon and boarding school was considered essential for the royal youngsters.

Being educated away from home was also regarded as a progressive choice at the time and encouraged the Queen’s four offspring to mix with children from different backgrounds.

According to his biographer, Jonathan Dimbleby, the Prince of Wales, in particular, hated being a boarder at Gordonstoun and was bullied.

The separation from his home accentuated the emotional distance Charles, a sensitive child, felt had opened up between him and his mother and father.

Even in later life, the relationship between the Queen and her eldest son, who was born in 1948 when Princess Elizabeth was just 22, was sometimes difficult.

The expression of mutual affection did not come easily to the older royals.

Courtiers have testified that the Queen was not a tactile mother and was not a natural at emotional hugging and kissing.

There were those, however, who considered the Queen showed firmness in every area of her life except with her children.

With his parents so often away, Charles’s nurse, Mabel Anderson, played a vital role in his life.

She became in effect surrogate mother and even in adulthood the prince would turn to Mabel as often as he would to his parents for comfort and advice.

Dimbleby wrote of how the Queen was absorbed in her own hectic schedule and would withdraw from friction or disputes, leaving the more abrasive Philip to police the family and discipline the children.

According to the Rt Rev Michael Mann, former Dean of Windsor and a close friend of the Queen, the monarch was upset by Charles’s criticism and felt she had tried to be as normal a mother as possible.

Yet the prince did tell Dimbleby that he recalled much happiness in his childhood and believed his parents had tried their best.

The Duke of Sussex appeared to suggest in 2021 that his father Charles and the Queen and the Philip had failed as parents.

Speaking on the Armchair Expert podcast when the family was still grieving after Philip’s death, the duke said he wanted to “break the cycle” of “genetic pain and suffering” for the sake of his own children.

He said of Charles: “He’s treated me the way he was treated, so how can I change that for my own kids?”

In 2002, Charles paid a warm tribute to his mother during the Golden Jubilee.

In front of 12,000 people at a pop concert in the grounds of Buckingham Palace, he turned to her, remarking “Your Majesty” before pausing to add “Mummy”, to the delight of the crowd.

Yet the Queen still looked a little uncomfortable at this public display of affection.

Charles declared: “We feel proud of you; proud and grateful for everything you have done for your country and the Commonwealth over 50 extraordinary years, supported unfailingly throughout by my father.

“You have embodied something vital in our lives – continuity.”

The Queen witnessed the turbulent breakdown of Charles’s marriage to his first wife the Princess of Wales, with Diana later dying tragically in a car crash.

The prince went on to wed his former mistress Camilla Parker Bowles and settled into a happy marriage with the new Duchess of Cornwall.

It was when Charles turned 70 in 2018 and the monarch was 92 that she gave perhaps her most affectionate tribute to her eldest son, branding him a “duchy original”.

At a glittering 70th private birthday party at the palace hosted by the Queen, she described him as “a dedicated and respected heir to the throne to stand comparison with any in history — and a wonderful father”.

She quipped in reference to Charles’ organic food brand famous for its biscuits: “This toast is to wish a happy birthday to my son, in every respect a duchy original.”

The Queen intervened to urge Commonwealth leaders to back Charles as the future head of the Commonwealth, and publicly endorsed Camilla to be Queen when the time came – a move which greatly touched the prince.

The Queen’s relationship with the Princess Royal was an easier one.

Anne, who was born in 1950, was in many ways a clone of her father.

Her headstrong ways were accommodated by the Queen who had already learned to make allowances for Philip.

They shared a love of horses – the Queen taught her daughter to ride – and Anne’s practicality, hard work and devotion to royal duty was much admired by both her parents.

She divorced her first husband Captain Mark Phillips, but without fuss, and the monarch appreciated her no-nonsense approach to life.

If the Queen was perhaps a less natural mother with Charles and Anne, observers said she appeared more relaxed and doting with her younger children, Andrew, now the Duke of York, and Edward – the Earl of Wessex.

Andrew, an uncomplicated, rumbustious child, was said to be her favourite and arrived in 1960 after a gap of almost 10 years.

During the 1982 Falklands War, when Andrew was on the front line as a Royal Navy helicopter pilot, the Queen’s fears and anxieties were no different from those of other mothers with loved ones fighting in the South Atlantic.

But the duke, who divorced but remained friends with his former wife Sarah, Duchess of York, became embroiled in a major royal crisis which ended his public role when he was about to turn 60.

He was forced to step down from royal duties in 2019 over his friendship with convicted sex offender Jeffrey Epstein after a disastrous Newsnight interview.

He was accused of lacking empathy for Epstein’s victims and for not showing enough remorse over his association with the paedophile.

The duke faced calls to speak to US prosecutors and the FBI, which intensified after his friend Ghislaine Maxwell was charged with recruiting girls for Epstein to sexually abuse.

Virginia Giuffre, who was trafficked by Epstein as a teenager, said in an interview with BBC Panorama that she was “horrified and ashamed” after an alleged sexual encounter with Andrew in London in 2001.

In 2021, Ms Giuffre started a civil suit against Andrew in America for allegedly sexually assaulting her when she was 17 and a minor under US law.

The duke categorically denied any form of sexual contact or relationship with Ms Giuffre, and insisted he did not recall meeting her, despite being pictured with his arm around her waist at Maxwell’s house.

But he later settled out of court, agreeing to pay Ms Giuffre millions of pounds.

The Queen did not speak publicly about the claims, but ahead of the settlement took the difficult but inevitable decision to strip her son of his honorary military titles, with Andrew also stopping his use of his birth-right HRH style.

The monarch was not prone to making rash decisions, especially where her children were concerned, and the move came more than two years after Andrew’s Newsnight appearance.

But ultimately, she was advised to act to protect the institution, casting her second son adrift to prevent him toxifying the monarchy brand in the year of her Platinum Jubilee.

There was great surprise, however, when just weeks later, Andrew escorted the Queen to the Duke of Edinburgh’s public memorial service.

It was taken as a sign of the monarch’s support for her disgraced son, but there was said to be great unease among both Charles and the Duke of Cambridge over Andrew’s central role.

Edward, the Queen’s fourth and last child, was the baby of the family and was born in 1964.

“Goodness what fun it is to have a baby in the house again,” the Queen told a friend.

“He’s a great joy to us all,” she said.

Royal biographer Sarah Bradford suggested that, in the 1960s, when Charles and Anne were teenagers and Andrew and Edward were still young children, the Queen seemed to have found a better balance between the demands of her work and her children.

Edward was the only one of the Queen and Philip’s children not to divorce.

He dropped out of the Royal Marines in 1987 and was the first child of a sovereign to actively pursue their own career.

He set up his own film and TV production company, Ardent Productions, in 1990, but faced criticism over claims that he used official royal trips abroad, funded by taxpayers, to drum up business for his firm.

Edward also enraged his brother Charles when Ardent was found filming at St Andrews University, in breach of a media agreement, shortly after Prince William began studying there.

In the Queen’s Golden Jubilee year of 2002, Edward and wife the Countess of Wessex finally announced that they would be quitting their businesses to become full-time royals.

They settled down into royal duty and the earl is heavily involved with the Duke of Edinburgh’s Award scheme, founded by Philip.

The earl and the countess had long been a dependable source of support for the Queen, particularly after the duke’s death.

Sophie had a close relationship with the monarch and the Wessex family lived in Bagshot Park, Surrey, just 10 miles from Windsor Castle.