The wonderful TV series The Crown, which managed to make riveting drama out of the life of the world's most boring woman, succeeded because it concentrated on a tragic and majestic theme: that being a member of the royal family means you can't do anything you want: Margaret couldn't marry Peter Townsend, Edward couldn't marry Wallis and keep the throne, his brother therefore became king, which was the last thing he wanted, Elizabeth couldn't take her husband's surname, he had to change his for being too German, etc.
Diana, raised in the upper echelons of the nobility, must have slept through this bit of Aristocracy 101.
While the other royals kept to the rules of discretion and sacrifice that were the quid pro quo for the rewards that came with the position, she wanted to enjoy those rewards without putting in the hard yards.
So, not liking what she found upon marriage, she went to war with her husband and his family. I wouldn't wish such a daughter or son-in-law on anyone. Throw in a couple of dragons and an army of eunuchs and it was pretty much Game of Thrones for a few years there.
It wasn't hard to stand out in a family whose most glamorous member up to that point had been the horsey one.
First, she overshadowed her husband. Then she overshadowed her sovereign.
Tony Blair, unctuously called her the Queen of Hearts. She became Mother Teresa in Valentino, performing good works while weighed down by the sort of jewellery only dynasties can accumulate.
Princess Anne is rumoured to have once allowed her royal stoicism to slip long enough to express bemusement at the way Diana got so much attention doing what Anne had been doing for years - her job - without being defied as result.
Diana's influence can clearly be seen in William and Harry, who have inherited her gift for passive aggressive feuding.
It's very sad for children when their mothers die young. It leaves scars. Most children cope without the benefit of a documentary.
This year, the young princes have been not at all subtly indulging in a vulgar public conflict with their father and stepmother.
To be fair, this vendetta is being enthusiastically waged on both sides. A hagiographical biography of Camilla appearing so close to the anniversary of Diana's death is merely the tit for her stepsons' tat.
Diana did change things.
Her precedent has set an example of entitlement to people: that you can have the prize without paying the price - an attitude that has now reached all corners of society.
She encouraged the pernicious trend for bleeding one's emotions as publicly as possible - now sanctioned as it were by royal appointment.
And she pioneered celebrity as a life mission, self-dramatising and turning every aspect of her life into a public one-woman show.
More than just the Queen of Hearts, she was actually the first Kardashian.
