Alexander Fleming was a Scottish microbiologist and physician. He is credited with discovering penicillin, the world's first effective antibiotic substance; a discovery that changed the course of history. He also discovered lysozyme, an antimicrobial enzyme which forms part of the innate immune system. In 1999, Fleming was named in Time magazine's 100 Most Important People of the 20th century list.
Howard Florey was an Australian pathologist and pharmacologist. He is best remembered for his role in the formation of penicillin, for which he shared the prestigious Nobel Prize in Physiology or Medicine with Alexander Fleming and Ernst Chain in the year 1945. Florey is credited with carrying out the first clinical trial of penicillin at the Radcliffe Infirmary in 1941.