Macrobius Ambrosius Theodosius, usually referred to as Macrobius (fl. 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. Macrobius's given name (praenomen) is unrecorded as is his family name (nomen). His recorded name is a series of three surnames (cognomina), properly ordered Macrobius Ambrosius Theodosius. This is what appears in the earliest surviving manuscripts of the Saturnalia and how he is addressed in the excerpts from his lost De Differentiis. He is called "Macrobius Theodosius" in both Cassiodorus and Boethius and was apparently known during his lifetime as "Theodosius": The dedication of De Differentiis is "Theodosius to his Symmachus" (Theodosius Symmacho suo) and he addressed as "the very greatest Theodosius" (Theodosi optime) in a dedicatory epistle to Avianus's Fables. This was mistakenly reversed in later manuscripts to "Ambrosius Theodosius Macrobius", which James Willis then used in his edition of the Commentary. Little is known for certain about Macrobius, but there are many theories and speculations about him. He states at the beginning of his Saturnalia that he was "born under a foreign sky" (sub alio ortus caelo), and both of his major works are dedicated to his son, Eustachius. His major works have led experts to assume that he was a pagan.