Almost nothing is known about the life of Diophantus (di-oh-FAHN-tuhs), and there is no mention of him by any of his contemporaries. A reference to the mathematician by Hypsicles (active around 170 b.c.e.) in his tract on polygonal numbers and a mention of him by Theon of Alexandria (fl. 365-390 c.e.) give respectively a lower and an upper bound for the period in which Diophantus lived. There is also evidence that points to the middle of the third century c.e. as the flourishing period of Diophantus. Indeed, the Byzantine Michael Psellus (latter part of the eleventh century) asserts in a letter that Anatolius, bishop of Laodicea around 280 c.e., wrote a brief work on the Diophantine art of reckoning. Psellus’s remark seems to fit well with the dedication of Diophantus’s masterpiece Arithmētika (Arithmetica, 1885) to a certain Dionysius, who might possibly be identified with Saint Dionysius, bishop of Alexandria after 247. The only dates known about Diophantus’s life are obtained as a solution to an arithmetical riddle contained in the Greek Anthology, which gives thirty-three for his wedding age, thirty-eight for when he became a father, and eighty-four for the age of his death. The trustworthiness of the riddle is hard to determine. During his life, Diophantus wrote the Arithmetica, the Porismata, the Moriastica, and the tract on polygonal numbers.