Lactantius, Divinae Institutiones (Divine Institutes)

Lactantius was a Christian rhetorician and apologist, tutor in later life to Constantine's son Crispus, whose Divinae Institutiones, written in the early fourth century CE during and after the Diocletianic persecution, is the earliest surviving systematic Christian argument that Virgil's Fourth Eclogue prophesied Christ. Lactantius reads the poem's golden-age child as Christ returning at the end of a thousand-year age rather than as his first birth, an interpretation Constantine himself would later argue in public on similar lines. As a primary source for the claim itself, this text records how the Christian reading first entered the tradition; it is not independent testimony to what Virgil meant when he wrote the poem three and a half centuries earlier.