360Alexander Fleming
Alexander Fleming was a Scottish doctor and scientist who discovered penicillin, the first antibiotic, in 1928. Returning to his London laboratory after a holiday, he noticed that a mould had killed the bacteria growing around it. Mass-produced in the 1940s by a team in Oxford, penicillin has saved millions of lives. He shared the 1945 Nobel Prize.
Fleming grew up on a farm in Ayrshire and studied medicine in London. During the First World War he saw many soldiers die from infected wounds, which drove his search for germ-killing substances.
Howard Florey and Ernst Chain at Oxford turned penicillin into a usable medicine, and the three men shared the Nobel Prize in Physiology or Medicine. Fleming warned early that misuse could make bacteria resistant.