Macrobius Ambrosius Theodosius, usually referred to as Macrobius (fl. c. AD 400), was a Roman provincial who lived during the early fifth century, during late antiquity, the period of time corresponding to the Later Roman Empire, and when Latin was as widespread as Greek among the elite. He is primarily known for his writings, which include the widely copied and read Commentarii in Somnium Scipionis ("Commentary on the Dream of Scipio") about Somnium Scipionis, which was one of the most important sources for Neoplatonism in the Latin West during the Middle Ages; the Saturnalia, a compendium of ancient Roman religious and antiquarian lore; and De differentiis et societatibus graeci latinique verbi ("On the Differences and Similarities of the Greek and Latin Verb"), which is now lost. He is the basis for the protagonist Manlius in Iain Pears' book The Dream of Scipio.