Autopsies that opened the body to determine the cause of death were attested at least in the early third millennium BCE, although they were opposed in many ancient societies where it was believed that the outward disfigurement of dead persons prevented them from entering the afterlife (as with the Egyptians, who removed the organs through tiny slits in the body). Notable Greek autopsists were Galen (BCE 129– c. 200/ 216), Erasistratus and Herophilus of Chalcedon, who lived in 3rd century BCE Alexandria, but in general, autopsies were rare in ancient Greece. In 44 BCE, Julius Caesar was the subject of an official autopsy after his murder by rival senators, the physician's report noting that the second stab wound Caesar received was the fatal one. Julius Caesar had been stabbed a total of 23 times. By around 150 BCE, ancient Roman legal practice had established clear parameters for autopsies.The dissection of human remains for medical or scientific reasons continued to be practiced irregularly after the Romans, for instance by the Arab physicians Avenzoar and Ibn al-Nafis. In Europe they were done with enough regularity to become skilled, as early as 1200, and successful efforts to preserve the body, by filling the veins with wax and metals. Until the 20th century, it was thought that the modern autopsy process derived from the anatomists of the Renaissance. Giovanni Battista Morgagni (1682–1771), celebrated as the father of anatomical pathology, wrote the first exhaustive work on pathology, "De Sedibus et Causis Morborum per Anatomen Indagatis" (The Seats and Causes of Diseases Investigated by Anatomy, 1769).