Aelius Galenus or Claudius Galenus (Greek: Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen (/ˈɡeɪlən/) or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of the most accomplished of all medical researchers of antiquity, Galen influenced the development of various scientific disciplines, including anatomy, physiology, pathology, pharmacology, and neurology, as well as philosophy and logic.