By Kate Meynell Pier Productions for BBC Radio 4

Chief women Freemason, Eileen Grey (pictures by Alice Rosenbaum)

There's only one thing more mysterious than Freemasons, and that's women Freemasons. The controversial brotherhood is widely thought to be a male-only preserve, but sisters, or should that be "brothers", are doing it for themselves.

Her title is The Past Most Worshipful the Grand Master - an odd title for a woman, but women Freemasons appear to have little truck with the politically correct trend for making titles gender-specific.

"I know I don't look like the Duke of Kent [her equivalent in male Freemasonry], but it's the same sort of situation," says Eileen Gray, CBE.

She is the head of The Honourable Fraternity of Ancient Masons, one of the two orders of women Freemasons in this country. The fraternity has been around for nearly 100 years and has a membership in the region of 1,000 women. Its headquarters are in north London, and there are lodges all across the country and overseas too.

The Freemasons here follow the same ceremonies and practices as their male counterparts, bizarrely even calling each other "brother".

"We were formed from the men and we followed the men in practice, we use their ritual and it comes naturally to be brothers in a Fraternity," says Ms Gray.

We did say 'he' regardless that we are women - but it seemed a bit silly, so we've allowed 'she' to creep in Eileen Gray Inside the Freemasons

The Junior Grand Warden adds: "We say Worshipful Master, brethren, it hasn't been adapted at all. At one stage we did say 'he' regardless that we are women. But it seemed a bit silly. So we now have allowed 'she' to creep in. But you can't really say worshipful mistress. That wouldn't sound right. So we use Worshipful Master too".

So, what sort of women want to be Freemasons?

Social workers, teachers, actors, judges, business women and housewives make up the ranks. But what are they looking for when they join?

"It means different things to different people," says Ms Gray. "It broadens one's outlook on life, and gives different interpretations. We see people come in who are not used to the business world, not used to learning the ritual, and as they learn the ritual, that gives them confidence in public speaking, and it's really nice to see so many people blooming with their self-confidence."

To the outside world, the women's main contribution is to charity - they hold collections at the regular meetings and the cash goes towards good causes, in particular hospices.

Death threat

Records show that women have been involved in Freemasonry as long ago as 1277, when a woman mason - the society's roots are in stonemasonry - was working on the carvings for the porch of Strasbourg Cathedral.

FREEMASON FACTS Worldwide fraternal organisation Members joined by shared moral and spiritual beliefs Secrecy of meetings has led to controversy It denies that membership is closed - anyone can join, they say

But the first woman to join a lodge was Lady Elizabeth St Leger from County Cork in 1735. Curious about the meetings her husband frequently held in the drawing room of their home, she hid in a cupboard to overhear what was going on.

The ruse came undone when, at the end of the meeting, her husband opened a cupboard and Lady Elizabeth tumbled out. Her fate hung in the balance - there was discussion about whether she should be killed so she could not divulge the secrets. Eventually, though, the men agreed she should be allowed to join their lodge.

In 1913 the first women's lodges were established in Britain. Mixed lodges had existed for a long time, mainly in France, but it took three pioneering women to break away and form the first three lodges, called Stability, Wisdom and Strength.

But, as with the male fraternity, there is uneasiness among wider society about the existence of such "secret societies".

"We are not a secret society we are a society with secrets," says Ms Gray. "People think that because something is secret there's got to be something wrong with it. And it's not particularly secret, but because it has its rituals within it, which are known to those that participate, it can sound weird to people.

Shunned by men

"But unless you belong to a golf club or a cricket club, you don't necessarily know the rules and regulations of that sport, and it should be viewed in the same way".

Ceremonial objects which derive from the link with stonemasonry

But suspicions persist, and until recently, were even held by their male counterparts, who did not recognise the women's movement.

Things have gradually changed - although the United Grand Lodge of England - a self-proclaimed "society of men" - would need to change its rules to give them full recognition, and this isn't on the cards.

However, one male Freemason conceded women take the academic side of Freemasonry as seriously, if not more so, than some of the men - and they learn their lines better too.