Alexander Fleming was born in Ayrshire on 6th August 1881, the son of a farmer.
At the age of 13, he moved to London where he lived with his older brother, Thomas. He entered the medical field in 1901, and studied at what is now the University of Westminster. He qualified with distinction in 1906. He then began researching at St. Mary's Hospital Medical School. He also was awarded a gold medal for the top medical student in 1908.
At St. Mary's, he developed his research skills under the guidance of bacteriologist and immunologist Sir Almroth Edward Wright, whose revolutionary ideas of vaccine therapy represented an entirely new direction in medical treatment.
During the war, Fleming served in the Army Medical Corps. He worked as a bacteriologist, studying in a makeshift lab. Whilst he was there he discovered that antibiotics were doing more harm to the body than good. He suggested that wounds simply be kept dry and clean, however his recommendations were largely ignored.
In 1928, Fleming noticed that mould had accidentaly grown on a culture dish. he noticed that it had formed a bacteria free circle around itself and he started to experiment on it further.
However, it was actually Australian Howard Florey and Ernst Chain, a refugee from Nazi Germany, two different scientists, who developed it further so it could be used as a drug. At first, supplies of penicillin were limited but by the 1940s they were being mass produced by the American drugs industry.