tragic death.The Princess of Wales sent the fateful note to interior designer Dudley Poplak in 1991 to thank him for pictures he had drawn for her 30th birthday.She told him: “I do wonder what the next 10 years will bring, the last 10 I have learnt a great deal in an interesting way.”A year later, Princess Diana stunned the world by announcing her separation from Prince Charles.Her death, aged 36, in a car crash followed in August 1997.Diana’s letter to Poplak, on Kensington Palace-headed