Macrobius Ambrosius Theodosius, commonly referred to as Macrobius, was a Roman who lived during the early fifth century. He is primarily known for his writings, which include the widely copied and read Commentarii in Somnium Scipionis ("Commentary on the Dream of Scipio"), which was one of the most important sources for Platonism 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.
The correct order of his names is "Macrobius Ambrosius Theodosius", which is how it appears in the earliest manuscripts of the Saturnalia, and how he is addressed in the excerpts from his lost De differentiis. Only in later manuscripts were his names reversed as "Ambrosius Theodosius Macrobius", which James Willis then adopted for his edition of the Commentary. Alan Cameron notes that Cassiodorus and Boethius both refer to him as "Macrobius Theodosius", while he was known during his lifetime as "Theodosius": the dedication to the De differentiis is addressed Theodosius Symmacho suo ("Theodosius to his Symmachus"), and by the dedicatory epistle to Avianus's Fables, where he is addressed as Theodosi optime.
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 ortos 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.
Which "foreign sky" Macrobius was born under has been the subject of much speculation. Terrot Glover considers Macrobius either an ethnic Greek, or born in one of the Greek-speaking parts of the Roman Empire, such as Egypt, due to his intimate knowledge of Greek literature. J. E. Sandys went further and argued that Macrobius was born in one of the Greek provinces. However other experts, beginning with Ludwig van Jan, point out that despite his familiarity with Greek literature Macrobius was far more familiar with Latin than Greek—as evidenced by his enthusiasm for Vergil and Cicero—and favor North Africa, which was part of the Latin-speaking portion of the Roman Empire.