Princess Diana is the ''most beautiful royal of all time'', according to ancient Greece's 'Golden Ratio' formula.

The late royal - who died in 1997 in a car accident in Paris, France - obtained the highest score when Harley Street surgeon Dr Julian De Silva ran the Golden Ratio analysis, which determines physical perfection by comparing features with a facial mapping technique.

He told the Daily Mail's Femail: ''Diana, [Duchess] Meghan and Kate [Duchess Catherine] are all very beautiful women.

''But when measured against the Greeks' Golden Ratio of physical perfection, Princess Diana comes out on top.

''She was several points ahead of Meghan and Kate and just pipped the stunningly attractive Queen Rania [of Jordan] to the title of most beautiful royal of all time.''

The Golden Ratio relies on symmetry to determine beauty and when taking measurements, ''the length of the ear must be equal to the length of the nose and the width of an eye should be equal to the distance between the eyes''.

Dr De Silva added: ''Princess Diana was a very narrow winner - there was less than 1 per cent between her score and those of Queen Rania of Jordan in second and Princess Grace who was a very close third.

''Diana scored highly for her face shape, the width of her nose, her brow area, her forehead and her eyebrows - which all got the top scores.

''Her lowest scores were for her chin and lips. Her lips are a little thin and ill-defined and her chin is less classical than some of the other women.''

Five 'most beautiful' Royal women - Data courtesy of the Centre For Advanced Facial Cosmetic & Plastic Surgery.

1. Princess Diana - 89.05 per cent

2. Queen Rania of Jordan - 88.9 per cent

3. Grace Kelly, Princess of Monaco - 88.8 per cent

4. Duchess of Sussex - Meghan Markle - 87.4 per cent

5. Duchess of Cambridge - 86.8 per cent