Alexander Fleming, a Scottish doctor and researcher, is remembered as the man who discovered penicillin, the first true antibiotic. Born on a farm in 1881, Fleming served as a military doctor in the First World War, where he saw thousands of young soldiers die from infections in wounds that were not themselves fatal. The experience convinced him that medicine urgently needed a substance that could destroy bacteria inside the human body without harming the patient.
The discovery itself was famously accidental. In September 1928, Fleming returned to his laboratory at St Mary's Hospital in London after a holiday and began sorting through dishes of bacteria he had left out. One dish had become contaminated with a common mould, and around the mould was a clear ring in which no bacteria were growing. Fleming realised that the mould was producing something that killed bacteria. He named the substance penicillin, after the mould Penicillium notatum.
Although Fleming published his findings the following year, penicillin did not become a medicine immediately. The mould produced only very small amounts of the active substance, and isolating it in useful form was technically difficult. For almost a decade, the discovery remained a curiosity. Only in the late 1930s did a team of researchers at Oxford, led by Howard Florey and Ernst Chain, develop methods of producing penicillin in quantities large enough to treat patients.
Mass production began during the Second World War, and the drug saved the lives of countless wounded soldiers and civilians. In 1945, Fleming, Florey and Chain shared the Nobel Prize in Medicine. Fleming himself always stressed that the age of antibiotics had been reached only through the combined work of many scientists.