'The date was 29 July, 1981, Prince Charles and Lady Di’s wedding day, and as the Queen arrived at St Paul’s Cathedral and waved to the crowds, two women in late middle-age, in shapeless, baggy dresses, shuffled with clumsy gait up to the television and waved and saluted back to her, unable to articulate speech but making excited noises.

It was a poignant moment, recalls Onelle Braithwaite, one of the nurses who cared for them. ‘I remember pondering with my colleague how, if things had been different, they would surely have been guests at the wedding.’

The two women were Nerissa and Katherine Bowes-Lyon – nieces of the Queen Mother and first cousins to the Queen – who had been incarcerated since 1941 in the Royal Earlswood Asylum for Mental Defectives, at Redhill in Surrey.'

Read more: Queen's Cousins Shuttered in a Mental Asylum