I have no surname. In 1979 I made a Statutory Declaration, that henceforth I would be known by only the first two names my parents gave me. Thus I dispensed with my ex-husband's family name, and rejected too the option of returning to my father's name (I loved him dearly, but I felt sure he would have supported me if he'd been alive). I thought at the time that I was doing something quite simple. I thought I was proving my independence from men, that as a woman I could stand alone. Now, 28 years later, at the age of 64, I am feeling under pressure. Computers, I am told, just cannot cope. I have to have a surname - "the computer will not accept a blank".

As a young woman growing up in the 1950s in north-west London, feminism was unknown to me. I was Margaret Chalker, and quite happy to be identified by my father's surname. Similarly I felt no pang when I married, in 1968, and swapped Chalker for O'Connor. But my pleasure at being a "Mrs" was severely undermined early on when I went to buy a spin dryer on hire purchase. The department store assistant refused to process the sale until my soon-to-be-ex husband had signed the form. As the main wage earner and previously trusted customer I was enraged, and incandescent later when my husband refused to give his signature. It was a trivial incident, but it coincided with the growth of the women's movement - and my growing involvement in it.

The marriage didn't last and we got divorced in 1975. For the next few years I continued to use my married name. But after a while this began to feel absurd. By the time I divorced I was active in various women's groups. I demonstrated at Greenham Common; marched on "Reclaim the Night" and read feminist literature, from Spare Rib to The Women's Press and Virago. I buried myself in my work as an English teacher. My social life was lived entirely through politics. It was a stimulating time and, influenced by the American feminist magazine by the same name, I started using "Ms" as my form of address. It is amusing now to recall how much resistance this caused. One insurance salesman went so far as to say it was essential to know if a woman was married as divorced women's cars sustained more damage - caused by their ex-husbands.

These experiences began to coalesce into a wish to be identified not as a wife, nor as a daughter, but simply me. Naming seemed important globally, too. I saw Southern Rhodesia pass through several names before the "new" country emerged as independent of colonial power. For myself, I did consider reverting to my mother's "maiden" name but this simply led back to my grandfather. Taking another name at random could lead to another male family tree. I considered possible neutral options such as "Window Cill" or "Door Jam" but knew I could not take the flak. Simply dropping both my "daughter" name and my ex-married name seemed the best option. Besides, my parents had chosen my first two names and it felt respectful to acknowledge their wishes.

Fearing dissuasion, I did not consult my family or friends as I embarked on this very serious, and at times ridiculous, journey around my name.

The headteacher of my south London comprehensive school was supportive; colleagues adapted and if they had views, I was not informed. My pupils were curious, respectful and gleeful at the prospect of addressing their teacher by her two first names instead of the more formal Ms O'Connor. For many of them, family names were already an issue, albeit not overt. In one school, a third of my year eight pupils had already changed all or part of their names due to their parents' divorce, remarriage or adoption. Many from other ethnic backgrounds had anglicised their family names.

So in February 1979 I became Margaret Sandra. "(Please use my name in full)," I would add in correspondence. It says a lot about my confidence at that time that I thought I need only ask for the change for it to be easily accepted.

Family and friends have been no problem, though I still get a few Christmas cards addressed to M Sandra. But banks, utility companies and the like have responded variously, particularly as their levels of computerisation increase. Getting my name under "M" in the phone book was no problem, though I know of friends who search for me under "S". I treasure my passport that recorded my "prenom" as "XXXX" and family names as Margaret Sandra.

At the time I changed my name, I had also largely given up on meeting a permanent partner. I had liaisons that lasted several years as well as shorter interludes, and in 1986 made a final decision to give up on men. That was when I re-met Iain. We were both attending an English teachers' conference and although we had known each other for more than 20 years, we had never talked at length. I discovered a kind, perceptive personality. From the beginning he was an invaluable supporter of my name. We are still together. I love him dearly.

Registering as a voter I found myself facing the local chief registrar himself on my doorstep, who blurted out as I opened the door, "Oh, you look quite normal!" Actually, I looked normal enough to be elected as a local councillor for 11 years and my electoral window posters had to be extra long to accommodate my name.

The problem is I have begun to feel rather defensive about my name. I perceive myself as a feminist and I expect others to recognise it. As a result, I find myself in increasing conflict with companies because their computer systems are unable to process my name. I have been turned down as a saver by a building society because its computer required me to have both a "Christian name" and a surname. Less powerful but more irritating is receiving two mail order catalogues, one to Margaret, the other to Sandra, amusing though it is to be perceived as a dynamic duo. I don't regret what I did nearly 30 years ago, but I have been explaining myself for so long I'm almost bored.

Would I have lived a different life if I hadn't made this choice in 1979?

By 28 I had already had two family names. Perhaps I needed to draw a line under my marital past and this was a way of starting afresh. I have been asked if I expected other women to follow my path, and what about their children's names? The only woman I knew who tried giving up her surname - an American called Vada who named her child Vada I - gave up, though I know there are others who have changed their name in different ways, and once knew a man called simply Bean.

I do feel I have achieved my intention - to challenge the custom of classifying all women by their relationships to men - but I never saw myself as a pioneer leading a movement. Naively, I thought my logic would gently spread and a new generation would be born, named temporarily as in Marge Piercy's novel Woman on the Edge of Time, until they were able to choose a name for themselves. A glorious fantasy thoroughly punctured by the progress of technology and its programmers. As for myself, I learned a long time ago that I was unable to have children, so I haven't had to deal with the question of what my own legacy or ongoing lineage would be. I'm not sure what I would have done if I had had a child.

I do worry, though, about what will happen when I die. The registrar of my mother's death seemed more concerned to record whose wife she was - Mrs Sydney Frank Chalker. When I go, will some bureaucrat, aided and abetted by software programmers, demand that I acquire a surname or they will not be able to register my passing? Whatever happens, I'll probably vanish from the genealogical tree, as has been the fate of significant numbers of women whose names are lost or forgotten in the sturdy march of male surnames.

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