Anton Thonius Philips van Leeuwenhoek was born in Delft, Netherlands on 24 October 1632. The son of a craftsman, he became interested in biology early on. When he was employed as an apprentice with a textile merchant, he discovered microscopes. At that time, they were used almost exclusively by clothmakers to see details in fabrics, but van Leeuwenhoek immediately understood the potential for other uses.
Van Leeuwenhoek went on to become a successful businessman. When he was still a university student, he already owned the largest drapery business in the city. In 1669, he earned a degree as a geographer and started working as a scientist almost immediately. This gave him an opportunity to reconnect with his fascination for microscopes. He started working on an improved version of the original microscope, in addition to creating a series of lenses and recording microscopic observations.
In 1676, van Leeuwenhoek was the first to observe single-celled organisms, such as bacteria and spermatozoa, using a microscope he designed. The discovery was first met with skepticism, but eventually recognized by the English Royal Society, leading to an appointment as a Fellow of the Royal Society, the highest scientific recognition at the time. Over the next 50 years, van Leeuwenhoek maintained a closed relationship with the Society, supplying a large number of original specimens and notes to the permanent collection. Because he could not draw, he hired an illustrator to provide accurate illustrations.
Van Leeuwenhoek built over 500 microscopes during his lifetime, ten of which have survived until today. These original microscopes were little more than magnifying glasses mounted on a brass plate. Although primitive by modern standards, his microscopes were a huge improvement over previous designs. They could magnify over 180 times, almost five times more than any other model available at the time. Van Leeuwenhoek is considered "the father of microbiology," and Charles Darwin elaborated the theory of evolution based on his observations.