Astrology was believed in and practised by all classes in the Late Empire. The Neoplatonist doctrine of a hierarchical universe provided an intellectual foundation for astrology which made it acceptable as a science and conferred on its practitioners new respectability and dignity. Only the Christians condemned astrology out of hand. And the frequency with which the Church Fathers repeat their denunciations of the art suggests that it had many adherents even in Christian communities. Shortly before the middle of the fourth century Julius Firmicus Maternus, a Sicilian of senatorial rank who had practised as an advocate, completed his handbook of astrology – Matheseos libri VIII. It is dedicated to Q. Flavius Maesius Egnatius Lollianus, otherwise Mavortius, comes Orientis 330–6, proconsul of Africa 334–7, Prefect of the City of Rome 342, consul 355, Praetorian Prefect 355–6, who had encouraged Maternus to write his manual.

In his first book Maternus defends astrology against sceptical criticism and alleges that he was the first to introduce the science to Rome. By this he means that he was the first to write a treatise on the subject in Latin. His claim is in fact unfounded, as Manilius had written on the subject in verse three centuries earlier. But Maternus may not have known of Manilius' poem, and the many resemblances between the two are likely to be due to the use of common sources in Greek. The remaining seven books set out in great detail, with many examples, the principles of the alleged science. Maternus' treatise is the longest and most systematic exposition of astrology surviving from antiquity.