The friends stripped off to put some middle-aged sex appeal into a variety of prim WI activities such as jam-making, baking and knitting - and it ended up changing their lives forever.
Miss February, Angela Baker, says,"Every year the WI ask for nice pictures of village greens and so forth for a traditional calendar, but this year a friend nudged me and said we could make our own 'Pirelli-style' nude calendar.
"We laughed about it and that was that. However, when my husband John became ill in February 1998 the idea came back to us to raise money for the Leukaemia Research Fund."
Sadly John died five months later but it gave the women - all aged between 47 and 68 - the incentive to launch the calendar in his memory. The result was a story which flashed around the world and led to international fame for the middle-aged models.
The original print run was just 3,000 calendars, but the group ended up selling 88,000 and raising a staggering £330,000.
Then, a story about their exploits appeared in the New York Times soon afterwards and this led to 250,000 more sales in the United States.
"We ended up selling more calendars than Britney Spears," says Angela.
Before long, the women were receiving calls from film companies and last year their story was immortalised in the acclaimed hit movie Calendar Girls, starring Julie Walters and Helen Mirren.
"One minute we were at home doing everyday things and the next we were being treated like stars," says Angela.
The women channelled all the money their received from the film and calendars towards leukaemia research, pushing their fundraising efforts to just under the £1m mark.
"John would be pleased as punch," adds Angela. "It was too late for him, but wouldn't it be fantastic if the fund found a cure for other people?"
The women are thrilled to receive a Pride of Britain Award and have lived up to the Rylstone WI motto - Seek Happiness In Achievement - in grand style.