More than prayer: Even the closed Carmelite sisters of Quidenham, shown here harvesting their own vegetables, live surprisingly dynamic lives

In Obedience, a new novel by Jacqueline Yallop about the closing of a French convent, the remaining nuns lament their imminent separation as they eat dinner together. Little by little, details such as the "baggy peel" of an old orange, the deafness of one sister and the incontinence of another accumulate to depict with aching candour their bleak little trinity and the demise of convent life. 

But how close is fiction to the truth? Catholic nuns in Western Europe certainly seem to be in decline. In England and Wales, the Conference of Religious counts around 6,000 members across 185 women's religious orders, but many communities are made up of just a handful of nuns. A recent study conducted by Compass found that 37 women entered holy orders in 1999. In 2009 this had fallen to just 21. By comparison, 15 men entered in 1999, rising to 26 in 2009. Of the trickle of new postulants choosing the religious life, many are not British-born but from Africa, Asia and Eastern Europe. Nuns have played a significant but often underappreciated role in British culture and history, from preserving national artifacts to pioneering women's education. But while Catholicism is growing, convents, it appears, are not.

Almost all convents now face real financial strain. To make ends meet, they are selling off assets, awakening their entrepreneurial spirits by creating their own order-branded produce, and opening their doors to paying guests. Indeed, the fashion for religious retreats, where stressed-out secularists can hole themselves up without BlackBerrys for distraction has even spawned an annual handbook listing over 200 programmes across the UK. Most convents now have their own websites, many with sisters' blogs, prayer podcasts and detailed question-and-answer pages on life in their communities. Yet we still know very little about nuns, despite their vigorous attempts at self-promotion.

Sister Teresa Keswick is a member of the closed Carmelite community in Quidenham, Norfolk. A former criminal barrister, she has been a nun for 27 years. She was educated at a French boarding school where a discernible reverence for nuns was instilled in the pupils: "Despite being a cradle Catholic I was very ignorant about nuns. We were once taken on a school trip to visit a Dominican order in Paris. I had absolutely no interest in joining them, but I knew they were there. Children are not educated at school about nuns. Even many Catholics these days just don't know we exist."