When they were young girls, they had no idea that artwork created by their grandfather would help form the basis of a nationally acclaimed play. And last night, they got to see part of their family history brought to life on stage.

When they were young girls, they had no idea that artwork created by their grandfather would help form the basis of a nationally acclaimed play. And last night, they got to see part of their family history brought to life on stage.

Susan Hughes, Nicola Rankin and Elizabeth Socratos were in the audience at Norwich's Theatre Royal to see The Pitmen Painters.

The play holds a special significance for the sisters as their grandfather, Andrew Rankin, was one of the original painters who inspired the production.

The show, set in the Northumberland town of Ashington in 1934, follows the story of a group of miners who tried their hands at painting.

Within a few years, they were big names in the cultural world, becoming close friends with avant-garde artists, and their work was snapped up by top collectors - all while they continued their day job down the mines.

Mrs Hughes, 53, who lives in Great Yarmouth, said: 'I remember our dad telling me that our grandfather went to art classes, but he didn't talk about it and our grandmother never encouraged it. I found one of his sketchbooks - he had a natural talent for it.

'We are very proud of him and wonder what he would've thought if he could see it now; that it's actually a play and going to Broadway. We wish our parents were here to see it. They would've been extremely proud.'

Their grandfather, who died from cancer in 1962, was a timekeeper at the mines and, although he is not one of the artists featured in the play, some of his fellow painters are.

The sisters, together with their other sister Julie, who now lives in Canada, spent their early childhood in Bahrain and visited their grandfather during holidays.

They still own some of his work and first became aware of the impact the Pitmen Painters had made when they visited the Woodhorn Colliery Museum in Ashington.

'We knew of the Pitmen Painters and that our grandfather was one of them, but we didn't realise how famous they had got until we went to the museum,' said Ms Rankin, who also lives in Yarmouth.

'It was quite emotional when we started to learn more about it. I think he would've been astounded by the interest it has generated.'

The story was first adapted for the stage after play writer Lee Hall, who penned Billy Elliott, picked by William Feaver's book, Pitmen Painters: The Ashington Group 1934-1984, in a second-hand shop.

The play, a Live Theatre and National Theatre production, will be at the Theatre Royal until this Saturday.

Tickets cost from �5. To book, call the box office on 01603 630000 or go to www.theatreroyalnorwich.co.uk