Media playback is unsupported on your device Media caption Inside a witches' coven, where the coming of the god of darkness is marked on the day also known as Halloween

In a riverside meadow in the Dorset town of Weymouth, a witch is using a broom to sweep a sacred circle in the grass.

The rest of the coven stand, some in hooded gowns, in a circle around an iron cauldron where a fire is burning.

They've met to celebrate Samhain, pronounced "sah-wen": the turning of the year from light into dark.

Many think of Halloween as a time of ghouls and ghosts, and for some retailers it has become the third most lucrative event of the year.

It is the time of year when some churches remember the souls of the departed.

For the witches of Weymouth it is one of their most important religious festivals, a time when they believe the barriers between the physical and spiritual worlds are at their thinnest.

It's feminist. Women have an automatic place... and in some areas of Paganism they are actually in charge Ronald Hutton, Professor of History, Bristol Uni

They invite the spirits of north, south, east and west into the circle, and cut apples to share with the spirits of people who have died.

The leader of the coven, Diane Narraway, bids farewell to the goddess of light, and kneels before the head of a horned ram, holding her hands out as if to a flame.

"I kneel before... the horned god, Lord of Witchdom, as we welcome him back to reign over the dark months," she says.

The coven meets regularly to make spells, using a variety of potions and differently coloured candles in order to achieve particular ends.

Green is for money, pink is for love

They say the spells are exclusively positive, and should be seen more as prayers.

Anouska Ireland, a 35-year-old teaching assistant, is wearing a hooded cloak in pale blue - the colour of good health.

Image caption Beth Irving and Teach Carter drummed to the site of the hand-fasting.

She says: "We sometimes use the cauldron to mix spells... it could be for the purpose of healing, and in harnessing positive intentions for someone who is unwell."

Sarah Sanford, a mother-of-three, uses spells to protect them.

"When my children are going to school I'll do a protection spell for them, so they get through the day all right," she says.

Among the youngest witches is Holly Syme, who says spells serve several purposes.

"You do a money spell, or you do a happiness spell, and it's giving you the motivation to go out there and get it as well. And it makes you feel better in a way," she says.

The coven is composed entirely of women, and as in other branches of Paganism, a particular regard for the female is driving its widening appeal in contemporary society.

Ronald Hutton, Professor of History at Bristol University, says Paganism is partly a reaction to a perceived discrimination against women, practised by mainstream religions.

We've come to a time, after thousands of years of dogmatic religion... for human beings to take hold of their spirit and become free Tony Jameson, Druid Bard

He says: "It's feminist. Women have an automatic place... and in some areas of Paganism they are actually in charge. And they're working with a goddess or goddesses who are just as powerful as gods, if not more so."

The increasing popularity of Paganism is visible in the Dolmen Grove, a group of Dorset druids.

It claims a total membership of around 1,000, double what it was a year ago.

Its leader, or bard, Tony Jameson, says Druidry is functioning more and more as a mainstream religion.

Spectacular headdress and horns

Wearing a spectacular headdress and horns, he presides over a wedding, or "hand-fasting".

Beth Irving and Teach Carter have their hands bound in coloured ribbons representing the elements of earth, wind, fire and water.

They drink mead and bread representing the blood and body of the earth.

It is symbolism strikingly similar to Christian practice.

Indeed modern Paganism is a reinvented religion, whose members seek the divine in nature.

Death and danger

It originated among ancient Celts for whom the natural world was a wilderness that brought them death and danger as well as sustaining life.

In contemporary Britain its members are more worried about the destruction of the natural world.

Although Paganism is largely a recent invention, and imposes very few constraints on its members, one important branch of it has been designated "officially" a religion.

Earlier this month the Charities Commission gave the Druid Network the status of a religion.

It said its worship of a supreme entity, its set of coherent practices, and its beneficial moral code, met the definition of a religion.

The Dolmen Grove does not belong to the Network, but Mr Jameson says the decision is hugely significant, a sign of official acceptance that religion need not be all about rules and a prescribed form of spirituality.

"We've come to a time, after thousands of years of dogmatic religion... for human beings to take hold of their spirit and become free. Free themselves of all the dogma, of all the rules and regulations, and let the conscience grow on its own," he says.

Cat Treadwell represents another sign of official acknowledgement of Paganism as a mainstream religion.

In her everyday life she wears the green uniform of an NHS ambulance worker.

But she is also listed by Derby NHS Trust as their Pagan Hospital Visitor - a kind of Pagan Chaplain.

At home, in the long hooded cloak she wears as a Druid priest, Cat stands at a small altar on which is the sculpted form of a woman, green leaves and an apple.

She lights a candle at a small altar for the patients she has tended to during the day.

"Druidry has changed a lot in the last 20 years in terms of public perception. It's now certainly more legitimate to actually go out now and call yourself a Druid. I generally get a little bit of fun (made of me) but people understand that it's a specific and serious faith," she says.

In the ruins of a church on Portland Bill in Dorset, the hand-fasting ceremony is reaching a climax.

The beat of drums reaches a crescendo as Beth and Teach run down what was once the church's nave and jump over a broomstick.

It is a leap into married life, and a religion whose members say its time has come.