Alexander Fleming was born in Ayrshire on the 6th of August 1881 to a sheep farmer. He moved to London when he was 13 and later studied to be a doctor. He qualified with distinction in 1906 and began research at St Mary's Hospital Medical School.
In WW1 he served in the army medical corps and was mentioned in dispatches. After the war he returned to St Mary's.
In 1928, whilst studying influenza, Fleming noticed a bit of mould had developed on a set of dishes being used to grow the staphylococci germ. The mould had created a bacteria free ring around itself.
He studied the mould further and named it pencillin. However Howard Florey and Ernst Chain who developed pencillin further so that it could be produced as a drug.
At first supplies of pencillin were very limited but by the 1940s it was being mass produced by the american industry. Fleming produced many papers on bacteriology, immunology and chemotherapy.
He was elected professor of the medical school in 1928 and emeritus professor of bacteriology at the University of London in 1948. He was elected fellow of the Royal Society in 1943 and knighted in 1944. In 1945 he, Florey and Chain shared the Nobel Prize in Medicine. Fleming died on 11th March 1955.