Sir Alexander Fleming (6 August, 1881 – 11 March, 1955) was a Scottish biologist and pharmacologist. He wrote many articles on bacteriology, immunology and chemotherapy. His best-known discoveries are the discovery of the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the mold Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Chain.
In 1999, Time Magazine named Fleming one of the 100 Most Important People of the 20th Century for his discovery of penicillin, and stated:
Fleming was born on 6 August 1881 at Lochfield, a farm near Darvel in Ayrshire, Scotland. He was the third of the four children of Hugh Fleming (1816–1888) from his second marriage to Grace Stirling Morton (1848–1928), the daughter of a neighbouring farmer. Hugh Fleming had four surviving children from his first marriage. He was 59 at the time of his second marriage, and died when Alexander (known as Alec) was seven.