For almost three centuries, the Royal Society’s fellowship was exclusively male, and its distinguished members included Isaac Newton, Charles Darwin, and Albert Einstein.

This changed in March 1945 when Marjory Stephenson and Kathleen Lonsdale became the first women elected as fellows, breaking a gender barrier that had stood since the society’s founding in 1660. Eighty years later, the Royal Society launched a series of events to commemorate this significant milestone in scientific history.

The election of Stephenson and Lonsdale wasn’t the first attempt to include women in the prestigious organization. In 1902, fellows had nominated physicist Hertha Ayrton, but this effort failed when the society sought legal opinions about its charter, which routinely used masculine terms. Questions were also raised about whether a married woman such as Ayrton met the legal definition of a person, as wives were considered the property of their husbands at that time.

“The legal opinion came back that fellows could not elect women, particularly if they were married,” explained Keith Moore, the Royal Society’s archivist.

After equal opportunities legislation was introduced in Britain in 1919, the society could have elected women, but it took another 26 years before they did so. According to Dame Jocelyn Bell Burnell, a Royal Society fellow and pioneering astrophysicist, the timing was no coincidence: “I think it was because of what women, in general, did during the war. They couldn’t be ignored any longer.”

Marjory Stephenson: Pioneer in Bacterial Biochemistry

Marjory Stephenson was born in Burwell near Cambridge and became a pioneer in biochemistry. In 1928, her groundbreaking experimental approach enabled her to isolate an enzyme from bacteria cells, forming the foundation for much of our current understanding of biotechnology, including antibiotic production and environmental microbiology.

Her textbook, “Bacterial Metabolism”, became a required reading for microbiologists worldwide. Professor Judy Armitage, a former president of the Microbiology Society, described Stephenson as “a meticulous, innovative scientist who laid the groundwork for all future studies of bacterial biochemistry, identifying the complexity of metabolic pathways and the ability of bacteria to respond to change.”

Stephenson trained a generation of biochemists who established major research groups worldwide. Despite her significant contributions, she often remains overlooked because she credited her students for their discoveries and did not seek personal recognition. She even chastised any protégés she thought were distracted from their science by pursuing fame.

Kathleen Lonsdale: Revealing Molecular Structures

Kathleen Lonsdale, born in Newbridge, Ireland, 1903, was a physicist recognized for her “outstanding contributions” to crystallography. In 1929, she illuminated how atoms are arranged in molecules by proving the structure of benzene—a problem that had stumped many prominent scientists. Her work revolutionized our understanding of molecular structures.

Lonsdale’s scientific accomplishments were paired with strong personal convictions. As a Quaker, she was dedicated to pacifism and promoting ethics in science. Dame Jocelyn Bell Burnell noted, “Lonsdale’s dedication to promoting ethics in science is something which I found particularly powerful and moving.”

Breaking the Fellowship Ceiling

To join the Royal Society in 1945, candidates needed at least two existing fellows to sign a printed certificate that stated, “We the undersigned propose and recommend him.” The word “him” was crossed out for Stephenson and Lonsdale—12 fellows signed Lonsdale’s certificate, and 17 signed Stephenson’s.

Both women had earned the respect of male Nobel Prize-winning colleagues and former presidents of the Royal Society. Physicist Sir William Henry Bragg supported Lonsdale, while biochemist Sir Frederick Gowland Hopkins supported Stephenson. Bell Burnell explained that other fellows had to “take notice” when such eminent scientists recommended women.

Despite this historic achievement, the media response was generally muted. Several newspapers ignored the women and their achievements, reporting only on the “brilliant careers” of male scientists receiving the same honour.

Election to the Royal Society helped Stephenson and Lonsdale break additional barriers for female scientists. In 1949, Lonsdale became the first woman appointed as a professor at University College London, where she headed the department of crystallography. A building at UCL now bears her name.

Fellow microbiologist Alexander Fleming persuaded Stephenson to become the first female president of the Society for General Microbiology in 1947. An alumna and fellow of Newnham College, Cambridge, she was made the university’s first reader of chemical microbiology shortly before she died in 1948—the same year the female undergraduates she taught finally began receiving degrees.

To mark the 80th anniversary, the Royal Society commissioned two documentary films about women’s lives and achievements. Space scientist and BBC presenter Dame Maggie Aderin-Pocock hosted the documentaries, joined by Bell Burnell and Armitage to uncover the legacies of these pioneering scientists.

The first documentary explored Stephenson’s work and visited Newnham College, where a chemistry laboratory was built for women who were denied access to university labs. The second film delved into Lonsdale’s achievements and featured her former PhD student, Professor Mike Glazer.

An exhibit of archival documents about their election to the fellowship will be displayed at the Royal Society’s London headquarters in July. The society also plans to host evening talks and networking events to promote women in science and collect data to understand gender diversity across scientific disciplines better.

Professor Alison Noble, Vice President of the Royal Society and chair of its Women in STEM committee, emphasized both celebration and reflection: “While we celebrate their remarkable legacy, we cannot ignore that women were only admitted to the Royal Society—an institution founded in 1660—as recently as 80 years ago.”

These commemorative activities aim to honour past achievements and inspire future generations. “Women have always played an active role in scientific research,” Noble added, “and as we continue to celebrate women past and present, we hope this will encourage and inspire scientists of the future.”

The belated recognition of women’s scientific contributions reminds us that talent and innovation exist across gender lines. The story of Stephenson and Lonsdale is an essential chapter in the ongoing effort to ensure that scientific institutions reflect the full diversity of scientific talent.