Herophilos

Herophilos (335 BCE – 280 BCE) was a Greek physician who lived in Alexandria, deemed to be the first anatomist.

He was known for his discoveries in one of which was that the brain was central to the human nervous system. During his lifetime, he was able to perform the dissection of human cadvers on a large scale.

He also extensively mapped out the blood system and measured the pulse with the aid of a water clock. In his thirst to understand human anatomy, he was said to have performed 600 vivisection on live prisoners.

Reference

 * Assassin's Creed: Origins – Discovery Tour