A founder member of the organisation in 1992, the current president hails from Port Elizabeth, South Africa.

A retired dermatologist, Saul particularly researches Lithuania due to family connections to Linkuva and Marijampole.

He is project director of the Centre for Jewish Migration and Genealogy Studies at the University of Cape Town's Kaplan Centre for Jewish Studies.

Elsewhere, he is involved with Jewishgen Inc - a subsidiary of the Museum of Jewish Heritage in New York, a member of the board of governors and deputy chairman-elect at the International Institute of Jewish Genealogy, Jerusalem.

Saul - who emigrated to London in 1980 - is also co-founder and chairman of the Genealogical Society's Southern Africa special interest group.

"I grew up in a reasonably observant, Orthodox environment and moved to Johannesburg after my father, David, died," he recalled.

"The other big thing for me was growing up in Habonim from seven to 18. I went on camps and annual seminars.

"People came from all over southern Africa - from the Congo downwards."

Saul, whose sister Judith lives in Israel, settled in north-west London and was involved in a number of business ventures.

His interest in genealogy started in childhood when listening to his grandmother, Chana Dvora, talk about Lita (Lithuania), his family and countryside.

"She lived on a farm in South Africa since 1905, but in a remote area some 100 miles from a city and never mastered English, speaking a garbled mix of Yiddish, Afrikaans, English and Russian," he noted.

"A kind and warm person, Chana Dvora spoke about her parents and described a little wooden house they had lived in Pamusha, now Pamusis near Linkuva."

The fall of the Soviet Union and establishment of an independent Lithuania made research possible.

Saul attended a Jewish book fair for a talk by Sallyann Amdur Sack on Russian Jewish archives in 1992.

The visit led to his role in the formation of the Genealogical Society with Graham Jaffay elected its first chairman.

Other founders included Michael Hanney, Doreen Berger, Dr Anthony Joseph and George Rigal.

"We started small with around 20 members, but grew rapidly into the hundreds and now have around 1,000 members," he said.

"We started developing meetings outside London in Bristol, Brighton, Manchester, Leeds, Leicester and Glasgow.

"The society grew, we held an annual conference and an international conference in 2001, which attracted around 800 people."

In terms of discoveries, Saul found the tombstone of his great-grandmother Grunia Girs in Linkuva, Lithuania.

The search began after Saul had been shown a school register for 1941 showing names of Jewish children crossed out in red ink with the dates when they had been killed.

He was taken to mass murder sites in the forest of Dvariulai and Veselkiskiai.

Armed with a photo taken by his father of his great-grandmother's tombstone when he went to Lithuania in 1923, Saul located a Jewish cemetery with the most recent tombstones dated 1939.

"There are no maps and no burial registers," he said.

"Few people in the town even knew of the existence of a Jewish cemetery."

Saul stumbled over a gravestone, partially covered in grass.

"The bricks had disintegrated and only the granite stone was still intact," he recalled. "It was as if I had been guided there by an invisible hand.

"We cleaned up the stone, rubbing it with fine sand and said kaddish. This gave me a sense of connection to my family and their past."

Saul discovered his grandmother had three sisters in Lithuania killed in the Holocaust.

"She and her brothers went to South Africa, four of her nephews also came later," he said.

"No one spoke about the family who were killed, but I had heard all their names over the years.

"Grunja Z, one of her nieces, my father's first cousin, survived the Siauliai and Riga ghettos, Stutthof and Dora Mittelbau concentration camps.

"She made aliya from Riga in the early 1970s. After many years of talking to her, I filled in pages of testimony on her behalf for Yad Vashem in 2008."

Subsequent visits to Lithuania, where Saul saw more than 100 of the estimated 230 mass murder sites, led to a research project with Dr Rose Lerer Cohen, of Jerusalem, and the publication of The Holocaust in Lithuania: a Book of Remembrance in 2002.

Saul has also edited two volumes of Jewish migration to South Africa and co-authored a book on destroyed European communities.

His research on Jewish cemeteries with photographs is online.

"It's not just a matter of collecting names and listing families," he said.

"The information is a tool for understanding Jewish history, for educating the younger generation and a broadening of an understanding of what it is to be Jewish.

"Jewish genealogy has also grown among non-Jews who had Jewish ancestors two or three hundred years ago."

As for future plans, Saul was enthusiastic about possibilities.

"We are working on a World Jewish Relief project on the Kindertransport, whose members want to know more about their families," he said.

"One of the difficulties is that younger people do almost everything on the web and those particularly with young families don't have the time to come to meetings.

"There is an imbalance in membership, but there is a lot of interest from schools.

"We work with Jewish day schools on family history projects.

"Applying modern technology to genealogy will only develop and help families in the future.

"The prospects through technology is limitless."

www.jgsgb.org.uk