Welsh mathematical great: Mary Warner

Gareth Ffowc Roberts writes about Mary Wynne Warner in his book G F Roberts, For the Recorde: A History of Welsh Mathematical Greats (University of Wales Press, 2022). We present below an extract from the text.

Mary Wynne Warner (née Davies)

Among those who were attracted by the modern algebra revolution was Mary Wynne Warner (née Davies). France and Belgium had led the modernisation campaign in Europe inspired by the Belgian mathematician and educator Georges Papy (1920-2011) and others.

In 1961 Papy published a book in French for college students and their teachers that presented a 'rigorous yet exciting introduction to a subject that has a central and fundamental position in modern mathematics'.

The book was published in English in 1964, having been translated and adapted by Mary Warner.


Mary Warner was inspired to specialise further in modern algebra, ultimately leading to her appointment as a professor of mathematics at City University, London, the first woman to attain that position at the university.

When her friends asked her to explain exactly what her field of research was and she struggled to do so in easily understood terms, she would also add, 'You mustn't think that I'm good at sums, because I'm not'.

Structure and pattern in mathematics was her delight, not sums.

Mary Warner's history reveals a heroic story. That history - or 'herstory' - is best understood within the context of women's uphill struggles to be allowed to excel in mathematics within a male-dominated culture.

In Britain, some women won the right to vote in 1918, but the prejudice that they suffered in education, particularly in the sciences, lasted well beyond that.

For example, women were not allowed to gain admittance to the University of Cambridge until 1869 and, even then, they were unable to graduate fully until 1948.

A woman admitted to study mathematics in Cambridge in 1930, say, and who had passed every examination during her course, would not receive a university degree.

At best, she would receive a certificate by post, but would be barred from attending a formal degree ceremony along with the male graduands and her certificate would not allow her to be a 'member of the university'.

Today, we may take it for granted that no woman is hindered from following a degree course in mathematics, but there is still some way to go to ensure that there is equity in terms of numbers.

As an example, roughly 30 per cent of the students studying mathematics at the University of Oxford are women.


Born in Carmarthen, the elder daughter of Sydney and Esther Davies, Mary attended a primary school in the town before the family moved to Llandovery and she to the local grammar school.

The family then moved to Holywell in Flintshire and Mary was admitted to Howell's School in Denbigh, where she sat her A levels.

She excelled at mathematics and won a scholarship to Somerville College, Oxford, gaining her degree in 1951 and embarked on doing research in mathematics. At Oxford she met Gerald (Gerry) Warner who studied history at St. Peter's College.

Shortly after they married in 1956, Gerry Warner, who by then worked as a government intelligence officer (MI6, essentially), was posted to the British Embassy in Beijing.

The voyage on board ship to China took seven weeks and Mary looked forward to beginning her duties as the wife of a diplomat.

At the same time, she was intent on continuing her mathematical work and was fortunate that Chang Du-Shen, one of her fellow researchers in Oxford, had returned to Beijing University and that they were able to meet to discuss their work.

However, this was the period of China's Great Leap Forward and the clouds of China's Cultural Revolution were gathering under the leadership of Mao Zedong, Chair of the Communist Party.

Many academics, including Chang Du-Shen, suffered as a result. On his final visit to Mary and Gerry's flat, such was his fear that he would be caught by the secret police that he hid behind the sofa and whispered that he would not be able to return to see them again.


In 1960 Gerry Warner was posted to Burma (now Myanmar) and the couple lived in the capital, Rangoon (now Yangon). Mary was keen to continue with her mathematics and applied for a post at the then Rangoon University.

The officials at the British Embassy initially refused permission for her to make the application, as explained by Gerry:
When we arrived in the Embassy in Rangoon in 1960, no wife of a British diplomat had ever been allowed to take a full-time job. Women were supposed to be addenda and supports to their husbands. How long ago it seems. In the event, the Ambassador gave way when it was made clear that Mary worked, or we left.

And she proved her worth to the Embassy, since she was at the University when the first shootings of students began, as Burma moved towards dictatorship, and [she] was the only Western witness to events that the Army tried to conceal.
While at Rangoon University Mary Warner established an MSc course in mathematics, the first of its type in Burma. Four years later, in 1964, Gerry Warner was posted to the embassy in Warsaw, capital of Poland, and Mary registered at the university to study for a higher degree.

By the time she had completed her thesis Gerry had been moved to the embassy in Geneva, Switzerland, and Mary returned to Warsaw to receive her doctorate from the Polish Academy of Sciences.

In keeping with the regulations of the Soviet Union, to which Poland then belonged, graduates were required to pass an examination in Marx-Leninism before receiving their degrees.

Mary was able to avoid that obstacle, thanks to her husband's diplomatic skills, by all accounts.

Looking back over that period, Gerry noted:
Mary was the first diplomatic wife to obtain a doctorate in a foreign country, and as in Burma, her familiarity with parts of the society that others could not reach made our lives much richer and more interesting. I was proud of the trail she blazed for other women in such an exemplary way.

It appears that Mary lost nothing of her Welshness despite the years she spent abroad. She could speak plainly and with a sharp humour but had to control her emotions in company so as not to cause any professional embarrassment to her husband.

However, things got slightly out of hand on one particular occasion at a diplomatic reception that she and Gerry had arranged during their time in Geneva, where tartes à la crème were the speciality of the house.

One of the guests undiplomatically began to poke fun at Welsh poetry, much to Mary's annoyance.

She was unable to retaliate directly but decided to throw one of the hotel's cream concoctions at her defenceless husband. She had no rationale for doing so, of course, but her action certainly cut the conversation short.

Following periods back in London, where Mary took advantage of the opportunities to lecture at City University and was made a Reader there in 1983 and established an MSc course, Gerry Warner was posted to the embassy in Malaysia and they lived in Kuala Lumpur.

During this period Mary was the first person to lecture at both the Malaysian and Chinese universities in Kuala Lumpur.


Gerry Warner was honoured with a knighthood on his retirement in recognition of his service at MI6, and they both returned to Britain in 1991.

Mary was awarded a chair in mathematics at City University and continued to publish extensively up to her retirement in 1996 and beyond.

She also placed great importance on lecturing at the university and tutored many home and international research students, and was highly respected and admired.

Mary Warner had three children, born abroad. They each had successful careers but both Sian and Jonathan suffered from mental problems and tragically committed suicide within a few years of each other.

It appears that Mary devoted herself to her academic work partly as a coping mechanism.

Fuzzy mathematics

Contrary to the more common pattern among mathematicians, Mary Warner's mathematical creativity did not wane with age and some of her best work was accomplished during her final years.

In her own words, her aim was 'to make precise the property of imprecision' and she made major contributions to what is referred to as fuzzy mathematics, an important branch of modern algebra that can be used to analyse imprecision.

Practical applications of the theory include such diverse problems as forecasting weaknesses in nuclear reactors and forecasting earthquakes.

After retiring from City University, her health having broken slightly, she continued with her mathematics and enjoyed attending international conferences.

A year before her death Mary Warner was working on a paper that she intended to present at a conference in Oslo and planned to spend six months as a visiting professor at a university in Brazil.

But that was not to be; she died peacefully in her sleep on 1 April 1988, at the age of sixty-five, while staying with friends in Spain. She was buried in the churchyard at Kennerton, Gloucestershire, alongside her parents and two of her children.


Mary Warner gained international recognition, but her fame was not without its challenges. On one occasion Professor Warner had accepted an invitation to address a prestigious conference at the University of Bahrain.

Gerry decided to accompany her on the trip and recalls the story:
"We were met at the plane by one of Mary's junior hosts, and taken to stay with one of my colleagues. Shortly after we had settled in I was called to the phone. It was our host, who told me that he understood that Professor Warner was a woman. I confirmed that was the case. He said that this would be difficult, for she would be lecturing to male students, and meeting male colleagues. Would she mind if she was categorised as an 'honorary man'?

I naturally consulted Mary, [who] said she would have no objection. The visit passed off very pleasantly. Our final lunch was in the male quarters of our host's house. At the end of the meal I became an 'honorary woman', and was introduced to his wife and family in the female rooms.
Sir Gerry concluded that 'the occasion could only have involved a lady academic, and exemplified in a benign way the peculiarities of being a comparatively early bird as a lady mathematician'.

Last Updated February 2023