 Ammonius’ father Hermeias, after studying in Athens under Syrianus (Head of School in Athens 431/2–437), returned to Alexandria, where he established the teaching of Platonism as an additional subject in the school of Horapollo (see below), alongside the principal curriculum in rhetoric. Ammonius’ mother Aedesia had been chosen as a young girl by Syrianus, a relative of hers, to marry Proclus, who would succeed their teacher Syrianus as head on the latter’s death in 437. When Proclus was kept from marrying her by ‘some god’, Aedesia was then married to Proclus’ fellow student Hermeias. From these details, it is clear that Ammonius, second of three sons of Hermeias and Aedesia (the eldest died in childhood), must have been born after about 435, presumably not long before 445. He seems to have been dead when Damascius (ca. 460-after 532) was writing his Life of Isidore or Philosophical History in 526, but alive in 517, when his course on Aristotle’s Physics was first published by Philoponus.