Theon

Theon (late 4th century), and Theon’s daughter Hypatia. All were active in Alexandria as professors of mathematics and astronomy, and they produced extensive commentaries on the major authorities—Pappus and Theon on Ptolemy, Hypatia on Diophantus and Apollonius. Later, Eutocius of Ascalon (early 6th century) produced…

The father of Hypatia, Theon of Alexandria (c. 335–405 ce), edited the Elements with textual changes and some additions; his version quickly drove other editions out of existence, and it remained the Greek source for all subsequent Arabic and Latin translations until 1808, when an earlier edition was discovered…

Hypatia was the daughter of Theon of Alexandria, himself a mathematician and astronomer and the last attested member of the Alexandrian Museum (see Researcher’s Note: Hypatia’s birth date). Theon is best remembered for the part he played in the preservation of Euclid’s Elements, but he also wrote extensively, commenting on…