Anton Von Leeuwenhoek is the pioneer of microscopy. He invented the first light microscope and discovered bacteria, yeast cells, microscopic life in water droplets, and blood circulation in capillaries.
Robert Hooke discovered cells when he examined a slice of cork under a microscope. The cork's compartments reminded him of a monk's room in a monastery, so he named them cells. He built upon Leeuenhoek's work and improved the compound light microscope.