‘Goodbye England’s rose, may you ever grow in our hearts,’ sang Elton John at her funeral. Diana dead? Her body lying in that coffin under the red and yellow flag, her two boys in heartbreaking step alongside their mother? The shock of it arrived in waves. Wave upon wave of disbelief.

The Princess of Wales was the most famous woman in the world, dazzling with the incandescence that fame bestows on its most graceful exponents. The idea that all that radiance, that intense young life had been snuffed out in a few cruel seconds in some scuzzy Paris underpass. No. Sorry. Category error. ‘And it seems to me you lived your life like a candle in the wind… Your candle’s burned out long before your legend ever will.’

Twenty years on, how is the Diana legend holding up? Well, there is no doubt that she changed the Royal family, and changed it for good. Diana altered irrevocably what it means to be royal.