Jan van Leeuwenhoek was a Dutch scientist born in 1632, known as the "Father of Microbiology." He is famous for his pioneering work in microscopy, having developed powerful lenses that allowed him to observe tiny organisms, which he called "animalcules." His discoveries laid the groundwork for the field of microbiology and expanded our understanding of the microscopic world. Van Leeuwenhoek's observations included bacteria, protozoa, and sperm cells, which he documented in letters to the Royal Society of London. His meticulous methods and detailed descriptions helped to establish the importance of observation in scientific research, influencing future scientists like Louis Pasteur and Robert Koch.