How photographer Anthony Grant caught the stars in his spotlight

It is quite a feat to persuade stars, John Gielgud included, to be snapped in your tiny bedroom. But Anthony Grant pulled it off 30 years ago when, as an unknown photographer, he snapped all manner of stars in his sleeping quarters at his mum's pad in Chelsea. Julie Walters put on a full suit of armour to pose as Joan of Arc and Dudley Moore dressed up as Queen Victoria. Joanna Lumley, meanwhile, chose to don a Henry VIII costume, stuffing her cheeks with cotton wool.

"My mum made Gielgud an omelette because he looked like he needed feeding up. She often supplied sitters with food. She loved the fact [that] household names were coming to the house," says Grant. "I had a friend at Berman's and Nathan's theatrical costumiers. They gave me free rein – the only outfit I couldn't find was a Tudor dress big enough for John Cleese."

Grant wrote a wish-list of people he had always wanted to shoot for a show to raise funds for the Royal Marsden Hospital, where his father died. The response was overwhelming; A-listers from Maureen Lipman to Peter Gabriel and Darcy Bussell turned up in his bedroom.

"I was falling over them in this shoebox of a room, which was 10ft by 15 ft maximum," he says. "First I took straight portraits, but then to spice it up, I asked them, 'can you imagine who you would have liked to have been if you weren't famous for being who you are?' Of course, some of then took it deadly seriously, such as Christopher Lee, who claimed to be a descendant of Charlemagne. I provided all the outfits and spent hours painting backgrounds in my bedroom."

These photographs are now on show in Portraits for a Purpose at London's National Theatre. It's a far cry from the original exhibition in 1984, at the Royal Court Theatre. "I took Granny's greenhouse apart in Sussex and used the glass to make frames for each portrait. I made a wooden box to collect money and [at the end of the show] carried it to the Royal Marsden Hospital."

Grant handwrote letters to everybody he wanted to meet. "I'd drop letters off at the stage door and pretty much everybody said yes," he says. "It was a magical period of my life." He is hoping to do a second series but fears A-listers today aren't so amenable.

'Portraits for a Purpose' is at National Theatre, London until 24 March (www.nationaltheatre.org.uk)