Herophilus, a physician of ancient Alexandria, was the first person to make accurate anatomical observations about the human body, enabled by the ghastly practice of vivisecting criminals, and is sometimes referred to as the Father of Anatomy. However it was Andreas Vesalius, a sixteenth-century physician and professor of anatomy at the University of Padua, who published the first authoritative work on human anatomy, De Humani Corporis Fabrica (On the Structure of the Human Body), based on the dissection of corpses.
By religious and civil law, the practice of dissecting cadavers had traditionally been proscribed in human society. But with the advance of the Italian Renaissance came a more encouraging attitude toward scientific research. Thus, the Catholic Church began to allow dissections to be performed for specific purposes: for example, to perform autopsies in cases of suspected crimes.
At this this time, the foremost authority on human anatomy for over a millennium had been the Roman physician Galen. It was standard practice for professors of anatomy to sit on a chair high above the medical students and read from the work of Galen as they dissected cadavers, since the corpses would be in various stages of decay in an age without refrigeration.
Vesalius became the first teacher to come down and join his students in performing dissections. In the process, he would come to realize that much of Galen's work on human anatomy, based extensively on philosophical and religious theory, was nearly worthless for an important reason: the ancient physician had never dissected a human corpse.