Jonny Spencer was initially engaged to Lady Anne Glenconner, then Lady Anne Coke.
Lady Anne was a maid of honour to HMTLQ carrying her train at the wedding and also great friend to Princess Margaret.
It was actually Anne and her husband Colin Tennant who gave Margaret land on the island of Mustique which became her favoured retreat throughout much of her life.
Jonny dropped Anne without even having the basic decency to inform her and was seeing the extremely juvenile Frances, daughter of the formidable Baroness Fermoy who was lady in waiting to the late Queen mum, behind her back.
Baroness Fermoy was a truly awful woman who famously put her personal ambitions and social standing before loyalty to her own daughter by supporting Jonny Spencer against Frances when she tried to gain custody of the then very young Diana and Charles and slightly older Sarah and Jane.
Jonny was a nasty bully who met his match in Raine McCorquodale , daughter of romantic novelist Barbara Cartland.
Raine was a very brash woman, universally hated by the children (who called her Acid Raine) and said to be absolutely sex mad which suited philandering Jonny very well.
Diana allegedly pushed her down the stairs on one occasion.