Terry O'Neill had photographed almost every significant figure of the previous four decades, but Amy Winehouse was someone he'd actively been waiting to shoot. Backstage at Hyde Park on 27 June 2008 - Nelson Mandela's 90th birthday concert - he finally got his chance. She was 24 years old.

"She had a great look," O'Neill said. "A big beehive, sailor-type tattoos - raw attitude and a lot of sass." She'd just performed Valerie and Rehab to nearly 50,000 people. The portrait he made backstage that evening captures exactly what he described: someone entirely at ease with who she were, completely present in the moment.

Three years later she was gone. What O'Neill caught that evening in Hyde Park - the swagger, the stillness, the unmistakable face - is one of the last great portraits made of her.