• Acta Ludorum Saecularium (CIL VI 32323). The inscribed contemporary record of the Secular Games, recovered in 1890 from the banks of the Tiber.
• Cassius Dio. Roman History, Book 54. The narrative spine for 23 to 17 BCE, including the moral legislation and the equestrian reaction in the Forum.
• Donatus. Life of Virgil. The Octavia scene and the account of Virgil's death and the deathbed request to destroy the Aeneid.
• Horace. Carmen Saeculare. The Secular Hymn, performed June 3, 17 BCE. Note the prayer for marriage and childbirth that directly references the Lex Julia.
• Horace. Odes, Book 4. The retrospective on the Parthian settlement.
• Macrobius. Saturnalia, Book 2. The Julia anecdotes, preserved from earlier sources.
• Propertius. Elegies, Book 3. Contemporary elegy on Marcellus.
• Res Gestae Divi Augusti, sections 6, 8, 14, 19–21, 29. Augustus's own account of the laws, the building programme, and the family arrangements.
• Seneca the Younger. Ad Marciam de Consolatione. The fullest ancient account of Octavia's grief.
• Suetonius. Life of Augustus, chapters 21, 29–30, 34, 63–64. The moral legislation (chapter 34), the literary circle, and the family arrangements.
• Tacitus. Annals, Books 1 and 3. Retrospective on the succession and on the moral legislation. The analysis of the Julian laws in Book 3, chapters 25–28, is the sharpest ancient critique of the legislation.
• Virgil. Aeneid, Book 6, lines 860–886. The Marcellus passage, in the descent to the underworld.

• Fantham, Elaine. Julia Augusti: The Emperor's Daughter. Routledge, 2006.
• Galinsky, Karl. Augustan Culture. Princeton University Press, 1996. Essential on the moral legislation and its relationship to the literary programme.
• Goldsworthy, Adrian. Augustus: First Emperor of Rome. Weidenfeld and Nicolson, 2014.
• McGinn, Thomas. Prostitution, Sexuality, and the Law in Ancient Rome. Oxford University Press, 1998. On the Lex Julia de Adulteriis and its enforcement.
• Syme, Ronald. The Roman Revolution. Oxford University Press, 1939.
• Treggiari, Susan. Roman Marriage: Iusti Coniuges from the Time of Cicero to the Time of Ulpian. Oxford University Press, 1991. The standard reference on Roman marriage law and the Augustan legislation.

This episode has been drafted primarily from Suetonius's Life of Augustus. Suetonius was writing in the early second century CE, a century after Augustus's death, with access to the imperial archives as Hadrian's private secretary. Almost all the physical description, the working habits, the superstitions, and the details of the household come from his Life. In the cases where they do not come from Suetonius, they are usually in Cassius Dio, writing another century later still from Greek-speaking Bithynia in Asia Minor—modern northwestern Turkey.

Both sources have limitations. Suetonius is thematic, rather than chronological. He groups anecdotes by category—ancestry, physique, virtues, vices, notable sayings, superstitions, death—rather than narrating events in order. This makes his Life of Augustus a strange reading experience for a modern biographer, because it is not really a biography, in our sense. It is a character portrait assembled from archival material and organised by theme. It is also, in places, organised to illustrate a moral conclusion Suetonius has already reached. When he reports that Augustus was moderate in his diet and modest in his household, he is not only telling us what the archive says. He is also telling us what a good emperor ought to look like, and holding Augustus up as the example.

Dio is more chronological, but further from the events and working, for this period, from sources he does not name. His account of the 23 BCE illness is the fullest we have. It is not necessarily the most accurate, because the details of a sickroom scene reach him across two centuries, and what he records may already have been shaped by the political uses to which the story was put.

What neither of them can see is the ordinary population of the empire. Augustan Rome had roughly a million inhabitants. The Italian peninsula had perhaps six million. The empire, from Spain to the Euphrates, held fifty or sixty million. Almost nothing in Suetonius or Dio is about any of them. The empire that Augustus administered through his correspondence did not, in the sources, contain the people it was administering. Tacitus's famous analytical verdict, quoted last episode, that the principate was built on grain for the people, bonuses for the army, and the sweetness of peace for everyone else, is, among other things, the rare ancient moment when one of the senatorial historians looks outside the senatorial chamber and names who the settlement was actually for. It was for the soldiers who got their pay, for the urban poor who got their grain, and for the propertied classes who got safety. The people it was paid for by were the provinces, which Augustus governed, but the sources do not describe.

That absence is the largest thing about the Augustan period that the literary tradition does not tell us. The archaeology is doing some of that work now. The inscriptions, the papyri from Egypt, the provincial census records—these are being used by modern scholars to recover the empire that Augustus built for other people to live in. In this episode, I have followed the literary sources because the character portrait is what they are best at, and because the question of who Augustus was as a person is the question the sources were actually trying to answer.

• Cassius Dio. Roman History, Books 52–53. The fullest narrative of the settlement years and the 23 BCE illness.
• Donatus. Life of Virgil. For the literary patronage relationships.
• Horace. Odes, Books 1–3. Published in 23 BCE, the same year as the illness.
• Res Gestae Divi Augusti. Augustus's own account, read as the official version.
• Suetonius. Life of Augustus. The indispensable source for character, physical detail, working habits, and household.

• Eck, Werner. The Age of Augustus. Blackwell, 2003. Short, rigorous, excellent on the mechanisms of the settlement.
• Galinsky, Karl. Augustan Culture. Princeton University Press, 1996. The standard modern account of the cultural programme and its poets.
• Goldsworthy, Adrian. Augustus: First Emperor of Rome. Weidenfeld and Nicolson, 2014. The best modern biography, particularly strong on the administrative improvisation of the early settlement.
• Syme, Ronald. The Roman Revolution. Oxford University Press, 1939. The foundational modern analysis, still essential after eighty-five years.

• Augustus. Res Gestae Divi Augusti (“The Deeds of the Divine Augustus”). Augustus's own first-person summary of his career and achievements, inscribed on bronze tablets and posted throughout the empire. The religious restoration is mostly in chapters 8, 10, 12, 13, 20, and 21—the temple restorations, the Janus closures, the Ara Pacis, the assumption of the Pontifex Maximus. Loeb Classical Library edition (with English translation).
• Cicero. De Divinatione (45 BCE). The Roman intellectual position on augury and divination, written by a sitting augur. Book One defends divination; Book Two demolishes it. Loeb Classical Library edition.
• Cicero. De Natura Deorum (45 BCE). The fullest ancient account of educated Roman thinking about the gods. Three speakers representing the Epicurean, Stoic, and Academic positions. Loeb Classical Library edition.
• Livy. History of Rome. Numa and his religious institutions are in Book 1. The first lectisternium is in Book 5. The Cybele arrival in 204 BCE is in Book 29. The Bacchanalian crisis of 186 BCE is in Book 39—the longest single ancient narrative of a Roman religious panic. Penguin Classics translation by Aubrey de Sélincourt for the early books; Loeb editions cover the rest.
• Lucretius. De Rerum Natura (mid-first century BCE). The major surviving Epicurean text, and one of the greatest works of Latin verse. Lucretius's systematic argument that the gods are real but irrelevant, that the soul dissolves at death, and that religion is the source of most human misery. Penguin Classics translation by Ronald Melville.
• Ovid. Fasti (early first century CE). The Roman religious calendar in verse—six surviving books, one for each month from January to June. The single best ancient source for the festivals and rituals that punctuated the Roman year, including the Cybele/Claudia Quinta episode in Book 4. Penguin Classics translation by A.J. Boyle and R.D. Woodard.
• Plutarch. Parallel Lives. The Life of Numa is the major ancient narrative of Rome's religious founder. The Lives of Caesar, Cicero, and Antony provide most of what we know about the religious dimensions of the late Republic—Caesar's election as Pontifex Maximus, Cicero's augural service, the propaganda war of the 30s. Penguin Classics translations available for all the relevant Lives.
• Senatus Consultum de Bacchanalibus (186 BCE). The surviving bronze decree, now in the Kunsthistorisches Museum in Vienna. One of the oldest surviving Latin prose documents and the contemporary record of the Bacchic suppression that Livy 39 narrates. The Latin text is in CIL I² 581 with translations widely available online.
• Suetonius. Divus Augustus. Augustus's biography. Chapters 30 and 31 specifically address the religious restoration programme, including the eighty-two temples and the management of the priestly colleges. Penguin Classics translation by Robert Graves.
• Virgil. Aeneid. The founding epic of Augustan Rome, and the most sophisticated single statement of the Augustan religious-political programme. Aeneas's pietas as the organizing virtue of the poem, the burning of Troy and the rescue of the household gods in Book 2, the descent and the parade of future Romans in Book 6. Robert Fagles translation (Penguin Classics) is the standard modern English version.

• Beard, Mary, John North, and Simon Price. Religions of Rome. Cambridge University Press, 1998. Two volumes. The standard modern scholarly treatment, and the work this episode draws on most heavily.
• Rüpke, Jörg. Religion of the Romans. Polity, 2007. A clear, sociologically-minded treatment of Roman religion as a system of social practice rather than belief. Particularly good on the institutional and political dimensions.
• Scheid, John. An Introduction to Roman Religion. Indiana University Press, 2003. The best short modern treatment for the general reader.