Alexander Fleming was born on August 6, 1881, in Lochfield, a rural area near Darvel in Ayrshire, Scotland.¹⁾

He was the third of four children born to farmer Hugh Fleming and his wife Grace Stirling Morton.²⁾

Fleming's family had humble beginnings, and he grew up in a farming community where he developed a love for nature and science.³⁾

At the age of 13, Fleming moved to London to live with his older brother, where he attended the Regent Street Polytechnic.⁴⁾

He later enrolled at St. Mary's Hospital Medical School in Paddington, London, to study medicine.⁵⁾

Fleming served as a Private in the London Scottish Regiment of the British Army during World War I, where he witnessed firsthand the horrors of infection and inadequate medical care.⁶⁾

After the war, Fleming returned to St. Mary's Hospital as a lecturer and researcher.⁷⁾

In 1928, Fleming discovered the antibiotic properties of penicillin while working with staphylococci bacteria.⁸⁾

He famously noticed that a mold called Penicillium notatum had contaminated a petri dish and inhibited the growth of bacteria around it.⁹⁾

This discovery led to the development of penicillin, the world's first antibiotic, which revolutionized medicine and saved millions of lives.¹⁰⁾

Fleming named the substance penicillin after the Penicillium mold from which it was derived.¹¹⁾

Despite his groundbreaking discovery, Fleming initially struggled to isolate and produce penicillin in large quantities.¹²⁾

It wasn't until the 1940s, with the work of Howard Florey and Ernst Boris Chain, that penicillin was successfully mass-produced and used as a medicine.¹³⁾

Fleming received the Nobel Prize in Physiology or Medicine in 1945, along with Florey and Chain, for their contributions to the discovery and development of penicillin.¹⁴⁾

In addition to penicillin, Fleming made other significant contributions to medicine, including the discovery of lysozyme, an enzyme with antibacterial properties found in tears and saliva.¹⁵⁾

Fleming's work on lysozyme helped pave the way for research on the body's natural defense mechanisms against infection.¹⁶⁾

He also investigated the therapeutic uses of other substances, such as the enzyme heparin, which is used as an anticoagulant.¹⁷⁾

Fleming was known for his modesty and humility, often downplaying his own achievements and crediting others for their contributions.¹⁸⁾

He was a dedicated researcher and spent much of his career studying infectious diseases and searching for new ways to combat them.¹⁹⁾

Fleming was a Fellow of the Royal Society and a member of numerous other scientific organizations.²⁰⁾

In 1944, Fleming was knighted for his contributions to medicine.²¹⁾

He continued to work at St. Mary's Hospital until his retirement in 1948, after which he served as Emeritus Professor of Bacteriology at the University of London.²²⁾

Fleming married Sarah Marion McElroy in 1915, and they had one child together, a son named Robert.²³⁾

Fleming was an avid sportsman and enjoyed activities such as golfing and fishing in his spare time.²⁴⁾

He was also interested in art and music, and he played the violin.²⁵⁾

Fleming was known for his quirky sense of humor and his love of practical jokes.²⁶⁾

Despite his success, Fleming remained grounded and retained his Scottish accent throughout his life.²⁷⁾

Fleming was deeply affected by the loss of his brother, who died in World War I, and he became a staunch advocate for peace. ²⁸⁾

He believed in the power of education and often spoke out against ignorance and superstition.²⁹⁾

Fleming was awarded numerous honors and accolades for his contributions to science and medicine.³⁰⁾