Influential Greek writer on medicine from Pergamum. A short biographical note concerning him is given by Bar ʿEbroyo (Chronicon Syriacum, ed. Bedjan, 53–4). His medical writings, together with his doctrine of the four humors, proved to be extremely influential and came to dominate medical thinking in both East and West for well over a thousand years. Numerous works of his were translated into Syriac, and an invaluable listing of these and their translators is preserved in Ḥunayn b. Isḥāq ’s Risāla, concerning his own translations of works by Galen. Sergios of Reshʿayna is the earliest of the translators who are mentioned. Only a few of the many Syriac translations survive (including some of those by Sergios); these are either in early mss., or incorporated into a large compendium (ed. Budge; the identification of passages by Galen was subsequently made by Schleifer).