Prince Charles's idea to publicly air the Queen's private cine film collection and film his mother and other royals commenting on them for a documentary was a masterstroke.
It was the most compelling royal documentary I have seen in years - giving real insight into the private lives of the royal family.
The Queen was remarkably relaxed and pin-point accurate about when and where the films had been shot and who was in them.
Not since the controversial fly on the wall "Royal Family" documentary of 1969, that hasn't been shown since apparently at the Queen's insistence, has there been a more revealing film.
The narration and script by the Prince of Wales was informative and touchingly personal. There was even footage of the late Diana, Princess of Wales at Prince Harry's Christening. So she was not air brushed out of royal history.
But it was the natural warmth between mother and son, the Queen and Charles, as they sat and reflected on the past that was most interesting, going someway to dispel talk of their so called awkward relationship.
I also loved the contributions by Lady Sarah Chatto, Princess Margaret's daughter, too - who looked very moved at seeing footage of her late mother, most of it for the first time.
Queen Elizabeth II's 90th Birthday Celebrations
This footage, much of it shot by The Queen and The Duke of Edinburgh themselves, gave a unique and personal insight into their family life, which I have found very touching.
The 70-minute film, from John Bridcut, was also revelatory. Princess Anne's assessment of her mother as a realist and pragmatist when asked if Her Majesty was an optimist was an interesting assessment.
William and Harry continued to portray themselves as the "Ant and Dec" of the royals – with flippant remarks.
Harry's comment that Philip was a "stud" made me wince, just a little.
But when interviewed separately they were both more thoughtful and incisive in their assessments of the Queen.
