She edited a number of works in collaboration with her father, the mathematician Theon, last director of the Museion that was the center of scholarship in the classical world. Among them was a commentary on the 13-volume Arithmetica by Diophantus, which plays a role in the novel. She also edited Theon's commentary on Euclid's Elements, which was likely the basis for every geometry text for the next fifteen centuries.
She probably wrote The Astronomical Canon, which was part of Theon's commentary on Ptolemy's Almagest – the book that defined the Western view of the universe until Galileo's discoveries in 1610. Although Ptolemy's geocentric theory was incorrect, his Almagest remains a model of rigorous mathematical exposition and in a roundabout way it led to the discovery of the Americas; Ptolemy was also a geographer, and he erroneously placed India far enough east to make Columbus's plan seem plausible. The compilation of Ptolemy's work that survived to let him be considered the ultimate authority at the beginning of the Renaissance likely derived from the edition prepared by Theon and Hypatia.
Our only first-hand source materials are the letters written to Hypatia by her student, Bishop Synesius of Cyrene, who addresses her as “mother and sister,” suggesting not only his great respect but caution appropriate to a married cleric (he was granted a dispensation to retain his wife when he assumed the bishopric). He clearly adored Hypatia and took pains to keep his letters on a lofty plane, lest she be irritated by his attention. Like many geniuses, Hypatia was likely a prickly personality, as evidenced by the only anecdote that offers an insight into her personal life, which has her hurling her menstrual rags at a lovesick student. One of Synesius's letters asks plaintively why she has not responded to his last letter. Despite his best efforts to remain scholarly the letter has a tone suggestive of unrequited love.
Hypatia became the fulcrum of a power struggle between the ambitious bishop Cyril and the Roman governor Orestes. Seen “often in the company of the magistrates” Hypatia had a rock star celebrity uncommon to women in that time. Cyril was irked to see the crowds of students waiting outside her house and he blamed her for his estrangement from Orestes. In an effort to assert Church authority he cultivated a religious police force called the Parabolani — a kind of Christian Taliban. One day, when she was riding in her “chariot” (more likely a coach) past the pagan temple that had been converted to Cyril's headquarters, a mob of Parabolani seized her, dragged her up the temple steps, and beat her to death with tiles. Orestes vanished from the historical record shortly after that — probably recalled by order of the regent Pulcheria. Cyril continued as Patriarch of Alexandria for three decades and was eventually canonized.
Hypatia was a mathematician, astronomer, teacher, editor, inventor, musician, and author. In March, 415 A.D. she was murdered by a mob of fanatics on the steps of The Caesareum in Alexandria, Egypt. She has become a symbol of martryed Reason, feminism, and Classical paganism.
The year of her birth is unknown. The Polish historian Maria Dzielska, arguing that the career path of a 4th century academic might parallel a modern one, suggests that Hypatia was born around 355, which would have made her 60 when she died. This chronology allows her to be significantly older than her more notable students, conforming to modern convention. One should bear in mind, though, that a Roman girl was a legal adult at the age of 12, and in an age when life was nasty, brutish and short, people did not have the luxury of prolonging childhood, adolescence and graduate school into their thirties.
In the novel Alexandria I assume along with most historians that Hypatia was born between 370-380. I've also assumed that she was as brilliant as her attainments suggest and she was likely a child prodigy along the lines of Mozart and Gauss. Historical accounts note her beauty and chastity, suggesting that she was fairly young when she died.