Aelius Galenus or Claudius Galenus, often anglicized as Galen or Galen of Pergamon, was a Roman and Greek physician, surgeon, and philosopher. 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.

Pergamon or Pergamum, also referred to by its modern Greek form Pergamos (Πέργαμος), was a rich and powerful ancient Greek city in Mysia. It is located 26 kilometres (16 mi) from the modern coastline of the Aegean Sea on a promontory on the north side of the river Caicus and northwest of the modern city of Bergama, Turkey.