WHO do you think you are? Probably not who you expect... Brenda Green's grandmother had always told her family that there was something important for them in her safe. When she died, in 1969, they discovered the "something important" wasn't, as they expected, a piece of jewellery, but a black-edged mourning card for someone they hadn't heard of.

"I was intrigued and naturally wanted to find out why this was so important. It took me 18 years to track down the full story," says Brenda. "It turned out we had a bigamist in the family - in the days when bigamy was still a hanging offence. What a guilty secret."

Now Brenda runs Yorkshire Ancestors - a family history research centre near Pickering, where people can track down their own family secrets - with or without bigamists.

Back in the 1970s, in those pre-computer days, Brenda had learnt how to find her way through censuses and family records. She did the family trees for both sides of her family and acquired, on the way, a number of research skills - not least the ability to read legal Latin - and some useful books... "trade directories, poll books, church records, a 1904 phone book, which I got in exchange for a chest of drawers in a local radio swap shop programme."

At the time, Brenda and her husband David were running an award-winning caravan park, but they were ready for a change. "I used to chat to visitors and some of them would look at the books I'd collected and start their own researches. I'd give them a few tips, some advice... It seemed like a good idea to combine the two."

She and David moved to the pretty village of Ebberston, between Pickering and Scarborough, opened some holiday cottages and started the Yorkshire Family History Research Library.

"We have two self-catering cottages and most people come here just to do the research. Their families can have nice days out while the researcher is busy in here."

As well as computers, they have an amazing number of books and records relating to Yorkshire - censuses, trade directories, poll books, parish records, school records, marriage records, 1672 hearth tax, such gems as the records of Leyburn Petty Session Bastardy Cases ("invaluable"), the Protestation Returns of 1641 - all stuff to make the amateur genealogist's heart sing.

"Leeds library, for instance, might have more about Leeds than we do, but no one has quite so much about Yorkshire all in one place."

Brenda's colleague, Janice Wood, a partner in another enterprise, whom she met through York Family History Society, comes staggering in with yet another thick book about Yorkshire which she has just electronically scanned, page by page, so that it is now available on CD - as are many of their books. Such as the Leeds Parish Registers 1722-1757, Kellys Directory for the North and East Riding 1905, the Yorkshire Poll Book 1742, the Bootham School Register for 1822-1935.

"And best of all, most of the books on CD are machine searchable, which saves a terrific amount of time," she says.

Janice, who's involved in a number of local history and archaeological societies - "she has 48 hours in her day," says Brenda - comes from a long family of hoarders. "My great grandfather hoarded all sorts of bits of paper, that were fascinating," she says. "I also have photos of portraits of my great great grandparents. So it was inevitable really that I should want to find out as much as I could."

TV programmes such as Who Do You Think You Are? have, of course, sparked off even more interest. "Although it's not always as easy as the BBC makes out," says Janice.

It's easier if you come from a wealthy family who are more likely to have their own records. "But it's just as good if you're a pauper or a criminal. Then you crop up in the names in the workhouse or at the petty sessions. Very helpful!" says Brenda. "It's the law abiding ones in the middle who can be trickier to trace."

Tracing family history is, they admit, utterly addictive. "Once you start, you can never really say that you've finished, You just want to keep on.

"It's the combination of a detective story, crossword puzzle and a jigsaw," says Brenda. "We have people coming here for the week and they start searching on Sunday morning and don't surface until Friday night."

People come from all over the world. One of the comments in their visitors' book is from a New Zealander. "Well worth the 10,000 mile journey," he wrote.

"But it's not a competition to find out how far you can go back," says Janice, "Family history is more than a list of names and dates, it's the complete picture, all the stories involved. These were real people."

"And it's something that's just yours," says Brenda, "Your family, your history, the people who made you who you are. People think they know, but once they get started, all sorts of surprises turn up. Illegitimate babies or bigamists are the least of it. Just think of the ancestors Jeremy Paxman and Stephen Fry turned up, totally unexpected."

As well as all the books and documents, twice a month they also provide two-hour workshops to get people started. "Computers have made things so much easier, " says Janice, "but there is nothing like looking at the original documents. So even if people have no knowledge of computers, we can start them off."

Janice also conducts research into Yorkshire families on behalf of other people. "Recently we had two separate inquiries from people in the Cayman Islands. It turned out both families originally came from Pickering and were related - but had no idea."

People are welcome to go and use the library for a fee, and they will also provide one to one tuition for £10 an hour.

"Tracing your family has nothing to do with living in the past, or wanting to escape the present," says Brenda, "Someone once said that he who doesn't look backwards, can never go forwards. And that seems to sum it up nicely."

l Yorkshire Family History Research Centre, Studley House Farm, Ebberston, Scarborough, North Yorks. YO13 9NR. Tel: (01723) 859285.

* www.yorkshireancestors.com

* Yorkshire Ancestors will be at a number of family history fairs and events this year, including York Race Course on Saturday, June 24; Ryedale Folk Museum, Hutton le Hole, August 12 and 13; Gateshead International Stadium on September9 ; The Milton Rooms, Malton on September 16 and Scarborough Spa on November 11.