Sir Alexander Fleming was a Scottish physician and microbiologist. He shared the 1945 Nobel Prize in Physiology or Medicine with Howard Florey and Ernst Chain "for the discovery of penicillin and its curative effect in various infectious diseases". This was the first antibiotic substance discovered. His discovery in 1928 of what was later named benzylpenicillin from the mould Penicillium rubens has been described as the "single greatest victory ever achieved over disease". The Nobel Prize in Physiology or Medicine 1945, announced October 25, 1945. Sir Alexander Fleming, Ernst B. Chain, and Sir Howard Florey, “for the discovery of penicillin and its curative effect in various infectious diseases”. Sir Alexander Fleming: born 1881, Lochfield, Scotland. Ernst B. Chain: born 1906, Berlin, Germany. Sir Howard Florey: born 1898, Adelaide, Australia. Wiki link Wiki link Wiki link Data: the Nobel Foundation (CC0).