Theon of Alexandria Theon of Alexandria Theon of Alexandria (; ; 335 – c. 405) was a Greek scholar and mathematician who lived in Alexandria, Egypt. He edited and arranged Euclid's "Elements" and wrote commentaries on works by Euclid and Ptolemy. His daughter Hypatia also won fame as a mathematician. Little is known about the life of Theon. He made predictions and observances of solar and lunar eclipses in 364 which show he was active at that time, and he is said to have lived during the reign of Theodosius I (379–395). The biographical tradition of the tenth century Byzantine "Suda" defines Theon
Aristobulus of Alexandria quoted by Anatolius. He is incorrectly named "Aristobulus of Paneas" in Rufinus' Latin translation of Eusebius' "Historia Ecclesiastica" (7, 32, 16). It is a wrong translation of the Greek ὁ πάνυ, "the Great". In addition, the author here quoted by Eusebius, Anatolius of Laodicea (270 CE), was mistaken in believing that Aristobulus was one of the 70 priests who translated the Torah into Greek (the "Septuagint") during the reign of Ptolemy II Philadelphus (3rd century BC). Anatolius of Laodicea incorrectly said that he lived in the time of Ptolemy Philadelphus. A further mistake in Rufinus' Latin translation of the Anatolius