When they first met at a dance in Melbourne, the Australian-born woman Charles nicknamed "Kanga" was 16 years old. Her life was troubled by illness from childhood, and later by mental health problems.
Her friendship with the Prince cooled when he met Camilla Shand (later Parker Bowles) four years later. But friends have said she was bitterly disappointed that she never resumed her role as confidante and adviser to the Prince, following the break-up of his marriage to Princess Diana.
She was cleared of cancer this summer, after a three-year battle, and had suffered since childhood from spina bifida. For the past 18 months she had been in a wheelchair after throwing herself from a first-floor window at a Surrey drug and alcohol rehabilitation clinic.
In June, Lady Tryon was sectioned under the Mental Health Act following "bizarre behaviour" which also placed her marriage under increasing strain.
Two weeks ago, she was flown back from India where she had been undergoing treatment from a Russian-trained doctor, Mosaraf Ali, after becoming seriously ill. Her condition became critical following plastic surgery to treat a bedsore.
In the last days of her life, Lady Tryon reverted to her maiden name, Dale Harper, after her marriage to Anthony Tryon, 57, ended with a decree nisi on 1 September. She was still awaiting the decree absolute when she went into hospital. She had been looking forward to celebrating her 50th birthday with a huge party for friends at the Ritz.
Her four children and her brother, Derek Harper, were with her when she died. A statement from her family said she would be remembered for her "tremendous vitality and zest for life". Her funeral will be private. Her mother-in-law, Lady Dreda Tryon, said: "We are very sad, but happy for her."Reuse content