Robert Hooke first discovered cells in 1665 at the age of 30. He made the discovery while examining thin slices of cork under a compound microscope and revealed his findings in his book "Micrographia."
Hooke described the multitude of tiny pores as similar to the walled compartments monks would reside in, calling them cells, the name they still bear today. At the time, Hooke did not know the true structure or function of his discovery, which turned out to be non-living cell walls. Anton van Leeuwenhoek later became the first person to examine a live cell under a microscope in 1674.