Cecil Belfield Clarke (1894–1970) was a trailblazing Barbadian-born physician, scholar, and civil rights activist whose contributions spanned the fields of medicine, education, and racial equality. His legacy is marked by his unwavering dedication to public health, his pioneering work in paediatrics, and his tireless efforts to challenge racial injustice in Britain during the early 20th century.

Born in Barbados on April 12, 1894, Clarke was a brilliant student who attended Combermere School before winning a prestigious scholarship to study in the United Kingdom. He enrolled at St Catharine’s College, University of Cambridge, in 1914, where he studied Natural Sciences. He went on to earn several medical qualifications, including the MB (Bachelor of Medicine), BChir (Bachelor of Surgery), and FRCS (Fellow of the Royal College of Surgeons of Edinburgh), making him one of the earliest Black doctors to achieve such accolades in the UK.

In the 1920s, Clarke established a medical practice at 112 Newington Causeway in Southwark, London. For over four decades, he served a diverse and largely underserved working-class population, including many Caribbean and African immigrants. His practice became a vital community resource. Remarkably, during the Blitz in World War II, when German bombs devastated much of South London, Clarke’s surgery remained partially standing despite severe damage. Even with one wall missing, he continued to treat patients, a symbol of his dedication and resilience.

Clarke’s most widely known medical contribution is Clarke’s Rule, a formula used to calculate the appropriate dosage of medication for children based on their weight. The rule is:

Child’s Dose = (Weight of Child in lbs ÷ 150) × Adult Dose

This simple yet effective formula became a standard reference in paediatrics for decades, particularly in community and pharmacy settings. Before the widespread availability of more complex pediatric dosing systems, Clarke’s Rule offered a safe and practical solution for adjusting adult medication dosages for children, thereby reducing the risk of overdose or underdose.

Beyond his medical achievements, Clarke was deeply involved in civil rights activism. He was a founding member of the League of Coloured Peoples (LCP) in 1931, one of the earliest British civil rights organisations dedicated to combating racial discrimination and promoting equality. The LCP’s executive committee included influential figures such as Dr. Harold Moody, Jomo Kenyatta, and C. L. R. James. Clarke also supported African and Caribbean students through his involvement with Aggrey House and the West African Students’ Union, and maintained correspondence with prominent Pan-Africanists such as W. E. B. Du Bois and George Padmore.

Clarke lived with his partner, Edward “Pat” Walker, at their home in Barnet, North London. As homosexuality was illegal in Britain during his lifetime, Clarke had to navigate his personal life with discretion. Despite societal constraints, he built a life of quiet strength, integrity, and impact.

Today, Clarke is remembered not only for his medical innovation and community service, but also for his critical role in advancing racial justice in Britain. His contributions continue to be recognised through academic awards, public exhibitions, and a commemorative blue plaque near his former practice. Clarke’s life stands as a powerful example of compassion, courage, and commitment to social change.