1. A UK-based Saudi businessman, who owns a French film distribution company, was one of the investors behind the controversial film.
2. Jessica Chastain was first cast as Princess Diana but dropped out due to scheduling conflicts.
3. Naomi Watts watched Diana's famous interview with Martin Bashir "obsessively" to capture her mannerisms.
4. Watts said that she found Diana the hardest character she has ever had to play.
5. Diana was partly filmed in Kensington Gardens, London where the Princess used to go jogging.
6. Naomi Watts is the only A-lister in the movie - the rest of the cast are relatively unknown.
7. Princess Diana's exact outfits were all recreated for the movie including all her famous dresses.
8. In preparation for the film, Naomi spent six weeks with a dialogue coach.
9. A prosthetic nose was used to give Watts the most accurate Diana appearance.
10. During filming, Naomi said she had visits from the late People's Princess in her dreams.