It may have been Brad Pitt’s night, but all eyes were on Angelina Jolie at the World War Z premiere in London on Sunday as the actress made her first public appearance since revealing her decision to undergo a preventative mastectomy last month.

Her dress of choice for the occasion? Custom-made from the atelier of arguably the hottest name in fashion right now: Hedi Slimane.

But of course.

The actress, philanthropist and mother-of-six was the picture of health in the black cross-front, sheer-panelled gown and happily signed autographs and chatted with the crowd. She told attendant reporters that she was feeling ‘great, wonderful’.

‘I'm very happy just to see the discussion about women's health expand and that means the world to me,’ she said. ‘After losing my mom to these issues, I'm very grateful for it, and I've been very moved by the support from people. I'm really very grateful for it.’

Jolie announced her decision to have both breasts removed in a feature entitled My Medical Choice, which was published in the New York Times in May. As a carrier of the BRCA1 cancer gene, she had been a given an 87% chance of developing breast cancer; after her treatment, this has now decreased to 5%.

'I choose not to keep my story private because there are many women who do not know that they might be living under the shadow of cancer,’ she wrote. ‘It is my hope that they, too, will be will able to get gene tested, and that if they have a high risk they, too, will know that they have strong options.’

She also praised the support of Pitt and their children and, last night, he returned the sentiment.

Asked how important it was to have her support at the premiere he said: ‘I've never not had support from her. I love her. It just brings you closer and makes you stronger.’