The engagement photos of Prince William and Kate Middleton were inspired by the mood at photo shoots with Princess Diana, photographer Mario Testino said.
The celebrity photographer told American Vogue that playing music by French singer Dalida — the same tracks used while he photographed Diana, William's late mother — was the secret to the royal couple's relaxed poses.
"The contrast of the contemporary informal music playing in the beautiful rooms with so much history caused a lot of laughter," he was quoted as saying.
Middleton was an "easy sitter" because of her natural grace, Testino said, adding that she was humorous but also appeared to have developed "a perfect sense of royal responsibility".
The Peruvian fashion photographer has worked with William many times in the past, and is a royal family favourite who captured some of the most iconic images of Diana.