Queen Elizabeth II was in despair and sadness when she watched the marriages of her three children fall apart although she did not show this in public.

In his book "Queen of Our Times: The Life of Queen Elizabeth II," author Robert Hardman talks about the monarch's private pain as the marriages of Prince Charles, Prince Andrew, and Princess Anne all came to an end. He said she may seem "outwardly stoic as ever" but she "was finding the divorce talks deeply upsetting."

He said a former member of the royal household recalled that "every now and then, there would be a glimpse of her despair." It distressed her much more than she let on," the staffer told Hardman according to an excerpt quoted by People.

The former aide recalled, "I said, 'Ma'am, it seems to be happening everywhere. This is almost common practice.' But she just said, 'Three out of four!' in sheer sadness and exasperation. One shouldn't underestimate the pain she's been through."

In the book, which is out on April 5, Hardman also interviewed Queen Elizabeth II's former press secretary Charles Anson. He told the author, "I don't remember a single occasion when I went to see her and she exclaimed, 'No! What next?'"

Anson remembered the British monarch never lost her cool during her horrible year, known as her "annus horribilis" in 1992. She lived through the fire in Windsor Castle and saw the breakdown of the marriages of Prince Charles, Prince Edward, and Princess Anne. She also had to hear about the scandals surrounding the Prince of Wales and Princess Diana.

"The issue was sometimes embarrassing, but she got on with it. It is immensely reassuring in those situations to work for someone who isn't knocked back," Anson said adding that through it all, Her Majesty was "never short; never irritable; completely steady."

Sir John Major, who worked closely with the queen during this period, added that "she will always put her head down and plough through them" because she "lived by the doctrine, 'This too shall pass.'"

Hardman said that Queen Elizabeth II used "stillness" amid the drama surrounding Prince Charles and Princess Diana. She learned this strategy from her father, King George VI. He claimed that she may have sometimes been "accused of being slow to act, there has never been a charge of panic" because "her default mode in the face of a crisis is stillness."

Queen ELizabeth II
Queen Elizabeth II on Sunday became the first British monarch to reign for 70 years Photo: POOL via AFP / Steve Parsons