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
Reign of Cleopatra and introduced relief efforts such as releasing grain from the royal granary. Both Ptolemy XII and Cleopatra VII found it necessary to debase Ptolemaic coinage due to financial troubles. No gold coins are known from Cleopatra's reign, while use of bronze coins was revived (absent since the reign of Ptolemy IX) and silver currency was debased roughly 40% by the end of her reign. Coins struck under Cleopatra's reign came from a wide geographical expanse, including sites in Egypt like Alexandria, but also the island of Cyprus, Antioch, Damascus and Chalcis ad Belum in Syria, Tripolis in Phoenicia, Askalon in