Theon of Alexandria
Theon (
ca. 335 ..
ca. 405 AD) was a scholar and the last director of the
Library of Alexandria in the
Museion, until it was demolished by the patriarch Theophilus on order of the emperor
Theodosius in
391 AD. He wrote some commentaries on important works by his
hellenistic predecessors, notably the
Almagest and the "Handy Tables" by
Ptolemy. Apparently he is the first author on the theory of "trepidation of the equinoxes", as an alternative to
precession.
Theon was the father of
Hypatia.
