Genealogy, the research and study of family history, is such a fascinating subject, so fascinating that it has been linked with addiction—not alcohol, gambling or drugs, but the sheer pleasure of finding new facts that lead on to more searching and another “high” when that leads to even more revelations.

My addiction started about 20 years ago when I was called upon to discern the full relationship of a distant family member after she had died without leaving a will. Britain has strict rules about who can inherit the estate of the deceased in such circumstances. If no qualifying living relatives can be found, an estate reverts to the government coffers.

My mother had always referred to the woman in question as a “cousin,” but what was the actual relationship? It was my task to discover. I began by searching all the papers in the woman’s house to see if a will would materialize. When that failed, I went to the Family Records Centre (FRC) in Central London to locate her birth certificate, seeking clues to her parents and their relationship to my mother’s parents. Data at the FRC indicates the names of a child’s parents, where the child was born, date of birth and the parents’ address. In most cases, it also supplies the name and address of the person registering the birth, if not one of the parents. A marriage certificate will include the names and, often, the occupations of the bridal couple and those of the respective fathers. A death certificate records the date, place of death and cause. In the case of the intestacy I was investigating, I found the woman’s birth certificate, which gave the parents’ names, but I could find no trace of the named father or of a marriage certificate. It transpired that she was illegitimate, which led to further complications, and I had to go back two more generations before I found the direct link to my mother’s family that I needed. Ultimately, I determined that she was a second or third cousin. Under English law, we were not allowed to inherit; so all the estate, bar a few expenses, went to the Treasury.

Despite the lack of inheritance, this treasure hunt inspired me to learn more about my mother’s family, the Costas, believed to have come from Spain or Portugal in the 18th century. I eventually learned that we are among the longest-settled Jewish families in England, a bit like the Pilgrims who made the trip from England to Massachusetts in the 1600s.

My mother’s brothers and sisters were part of a large family. According to family legend, her parents (my maternal grandparents), Solomon (Solly) and Kate, had 21 children, but this was in the late 19th and early 20th century. By the time I was about eight or nine, I knew no fewer than 13 of them, many married with families of their own. I remember at a wedding in 1947 saying that if ever all the Costas wanted to get together, we would need to hire London’s Royal Albert Hall. Today, the joke is that we would need the new Wembley Stadium

Of course, many of us only get into the business of trying to trace family members late in life, too late, usually, to quiz the older generations, our parents and grandparents. So we must rely on family memory and the records kept at the FRC and other places. Because the Costas are Sephardic Jews, I consulted the published records of the Sephardic or Spanish and Portuguese Congregation at Bevis Marks Synagogue in the City of London, copies of which are held in many libraries and in the London Metropolitan Archives. Originals are safely housed in the Sephardic synagogue in North West London and are not available for public consultation, although copies of ketubot (marriage certificates) are supplied by the congregation for a fee. These usually show the original signature of the bridegroom; in the rare cases when the document is not signed by the groom, this is stated in the published records. Thus, it can be exciting when ordering and receiving a ketubah to see the actual handwriting of one’s ancestor. The Bevis Marks records go back to about 1656, when Jews were officially allowed to return to England after having been expelled in the 13th century.

All this sparked increased interest. Who were my maternal grandparents? Where did they come from, where were they born; what was my grandfather’s occupation? By the time I knew him, he had already retired. My grandparents, Solomon (Solly) and Kate Costa, lived in North London, an address we visited regularly almost every weekend in my early teenage years, meeting there my many uncles, aunts and cousins.

I logged on to the Genesreunited website, www. genesreunited.co.uk, a genealogical site that aims to help people seeking lost relatives or ancestors. In January 2006, I posted a message saying that I was interested in finding out about the family of Solomon Costa. Through this I made contact with Gary Nelson, a Costa relative.

Through Gary, I made contact with London taxi-driver Albert Farache and, via Albert, with Malcolm Laird, another Costa cousin, who lives in Australia. Over a number of years, Malcolm had created a CD-ROM that listed the family from 1746 when our common ancestor, Raphael da Costa and his wife, Ester da Costa, journeyed to England from Portugal. Raphael was, we believe, a converso, a hidden Jew, born about 1725. On his arrival in London on April 5, 1746, he made contact with the Spanish & Portuguese Congregation, which, by that time, had a synagogue in Bevis Marks in the City of London. The congregation may well have arranged the passage. Old Bevis Marks rec­ords show that philanthropic members of the congregation often helped their less fortunate co-religionists in a number of ways; immigration would have been one of them.

Raphael was circumcised at Bevis Marks on April 20 at age 21 within 15 days of his arrival. (Bevis Marks tradition at the time required those who wished to join the congregation to be circumcised [if not already] within 15 days of notifying the synagogue of their arrival.) He married five days later. At about the same time, Ester was required to undergo a ritual bath (mikvah). Because both parties were already using the same surname, da Costa, it is not unreasonable to believe that they had already married in the Catholic rite in Portugal. As yet, however, we have been unable to research that further. We believe that the couple wanted to regularize their position among English Jewry.

The Costa surname has many variations, including da Costa, de Costa, Gomez da Costa, Nunes da Costa and Mendes da Costa, but only the family of Gabriel Raphael Costa removed the prefix da from its name. We know this because the Bevis Marks records of the time show an entry for “Gabriel Raphael Costa, son of Raphael da Costa.” Therefore, any descendants of Jewish Costas who lived in England in the 18th century almost certainly are related to my family.

Gabriel Raphael and Ester’s son, Isaac Costa (born 1772), grandson of Raphael and Ester, was a schoolmaster and rubi (a kind of assistant or clerk to the rabbi) of Bevis Marks Synagogue. As such, he acted as an official witness at marriage ceremonies in the synagogue. Curiously, Isaac’s marriage to his wife, Sarah, is not among the synagogue’s records. We think that they may have married abroad. Their son, Raphael, also does not appear in the records, supporting the suggestion that they lived abroad for a number of years.

In collating various disparate bits of information, Albert Farache discovered the will of John Jacob Costa (born April 7, 1838; died April 22, 1873). John Jacob left his second bedroom furniture to his wife, Reyna, as part of her inheritance. Could he have been a devotee of William Shakespeare, who left to his wife his second-best bed?

London lawyer Gary Nelson already had begun his research when we made contact and had created a family tree with many names already familiar to me. His forte is in the collating of information from various sources. Now, of course, with all the family members coming out of the woodwork, so to speak, he has an even harder task updating all the information that has been supplied, and is still being supplied, to him. We now have data on about 10 generations of the family.

In June 2006, Cindy Collick, wife of Rabbi Jeremy Collick, minister of the Edgware Masorti Synagogue, hosted a family reunion in London attended by about 100 relatives from around the world. We live across Britain; in various parts of the United States, including Ohio and Florida; Israel; Australia; New Zealand; South Africa; France; and Canada; almost certainly also, still in Portugal and/or Spain. (Since Raphael and Ester undoubtedly left family behind in Portugal, presumably still living as Catholics, there may be descendants there today unaware of their Jewish roots.) We represent a wide variety of trades and professions from company director to wine grower, lawyer, journalist and London cabbies, to electronics specialist, pharmacist and even the owner and operator of an Australian sapphire mine. Some of us are seniors, others have young families. All this research will help our children, we hope, to know who they are and where they come from.

In the meantime, it is a fascinating hobby. The only problem is that there is never any end in sight. The more you discover, the more you realize that there’s more out there, somewhere. Genealogy is indeed fascinating, even, dare I say it, addictive, like alcohol or tobacco, though far less dangerous and far more enjoyable.