Today In History logo TIH
Alexander Fleming

Historical Figure

Alexander Fleming

1881–1955

Scottish physician and microbiologist (1881–1955)

Postwar

Hear Their Voice

Original recordings and AI voice

Original Speech

"BBC Science Notebook: Discovery of Penicillin" — August 28, 1945

AI Voice Clone

Generated by Today in History

Talk to Alexander Fleming

Have a conversation with this historical figure through AI

Key Dates

Biography

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".

Source: Wikipedia · Compiled March 2026 · AI-summarized

Timeline

1881
Birth

Scottish scientist, Nobel laureate (d. 1955)

August 6 →
1928
Event

"When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionise all medicine by discovering the world's first antibiotic, or bacteria killer," Fleming would later say, "But I suppose that was exactly what I did.” By 1927, Fleming had been investigating the properties of staphylococci. He was already well-known from his earlier work, and had developed a reputation as a brilliant researcher, but his laboratory was often untidy. On 3 September 1928, Fleming returned to his laboratory having spent August on holiday with his family. Before leaving, he had stacked all his cultures of staphylococci on a bench in a corner of his laboratory. On returning, Fleming noticed that one culture was contaminated with a fungus, and that the colonies of staphylococci immediately surrounding the fungus had been destroyed, whereas other staphylococci colonies farther away were normal, famously remarking "That's funny". Fleming showed the contaminated culture to his former assistant Merlin Price, who reminded him, "That's how you discovered lysozyme.” Fleming grew the mould in a pure culture and found that it produced a substance that killed a number of disease-causing bacteria. He identified the mould as being from the Penicillium genus, and, after some months of calling it "mould juice", named the substance it released penicillin on 7 March 1929. The laboratory in which Fleming discovered and tested penicillin is preserved as the Alexander Fleming Laboratory Museum in St. Mary's Hospital, Paddington.

September 28 →
1928
Event

Alexander Fleming notices a bacteria-killing mold growing in his laboratory, discovering what later became known as penicillin.

September 28 →
1928
Event

Alexander Fleming découvre la pénicilline.

September 3 →
1955
Death

Scottish biologist, pharmacologist, and botanist, Nobel Prize laureate (b. 1881)

March 11 →

More from the Postwar

Explore what happened on the days that shaped Alexander Fleming's life. Today In History connects historical figures with the events, births, and deaths that defined their era. Browse all historical figures or explore today's events.