Who First Discovered Microorganisms and When?

The first person to discover and provide a detailed description of microorganisms (or "microbes") was Antonie van Leeuwenhoek (also spelled Antonj), a Dutch draper and scientist from Delft, Netherlands.

His most significant discoveries occurred in the 1670s. While he began building microscopes in the early 1670s, his landmark observations that revealed the microbial world began around 1674.

The Key Discovery: "Animalcules"

In 1674, Leeuwenhoek took a sample of water from a nearby lake (Berkelse Meer) and examined it under his powerful single-lens microscope. To his astonishment, he saw a world teeming with tiny, living creatures, which he famously called "animalcules" (Latin for "little animals").

He described them as moving with great purpose, in various shapes and sizes. This was the first-ever observation of microorganisms, including what we now know as bacteria and protozoa.

• When: The first observations of microbes were made around 1674, with his findings communicated to the Royal Society of London in a famous letter in 1676.
• Who: Antonie van Leeuwenhoek (1632-1723).
• What: He discovered single-celled organisms, including protozoa (which he saw first) and bacteria (which he observed a few years later from dental plaque).

Because of this revolutionary discovery, which opened up the entire field of microbiology, Antonie van Leeuwenhoek is widely regarded as the "Father of Microbiology". He was the first human to ever lay eyes on the microbial world.