Chaeremon of Alexandria in Wikipedia
Chaeremon of Alexandria (1st century CE) was a Stoic philosopher, historian, and grammarian.
Chaeremon was superintendent of the portion of the Alexandrian library that was kept in the Temple of Serapis, and as custodian and expounder of the sacred books he belonged to the higher ranks of the priesthood. In 49 he was summoned to Rome, with Alexander of Aegae, to become tutor to the youthful Nero.
He was the author of a History of Egypt; of works on Comets, Egyptian astrology, and Hieroglyphics; and of a grammatical treatise on Expletive Conjunctions! Chaeremon was the chief of the party which explained the Egyptian religious system as a mere allegory of the worship of nature. His books were certainly not intended to represent the ideas of his Egyptian contemporaries; their chief object was to describe the sanctity and symbolical secrets of ancient Egypt. Chaeremon's works are now lost, but because later authors quoted from his works, fragments have been preserved.
He can hardly be identical with the Chaeremon who accompanied (c. 26 BCE) Aelius Gallus, prefect of Egypt, on a journey into the interior of the country.