On August 9, 48 BC — the same calendar date, by a coincidence historians have noted, as the Battle of Adrianople 426 years later — Julius Caesar’s army defeated Pompey’s at Pharsalus in Thessaly, ending the civil war between them in a single afternoon and ending the Roman Republic as a functioning political institution in any meaningful sense. The Republic would survive in form for another seventeen years, until Augustus completed its constitutional conversion. But Pharsalus was where it ended in fact, because Pharsalus eliminated the only man with the political authority, military reputation, and institutional support to contest Caesar’s supremacy on terms the existing system could legitimate.

Giovanni Battista Piranesi arrived in Rome in 1740 at the age of twenty and spent the rest of his life there, producing approximately one thousand etchings of the ancient and modern city that changed how Europeans understood ruins and, through ruins, understood time. His Vedute di Roma — the Views of Rome — documented the ancient monuments with a precision that made them available to architects, scholars, and artists across Europe who could not travel to see the originals. His Carceri d’Invenzione — the Imaginary Prisons — invented spaces of impossible scale and mechanical complexity that influenced the visual imagination of the Gothic tradition, science fiction, and everything in between. His archaeological publications — the Antichità Romane — were serious scholarly contributions to the understanding of Roman building techniques. He was simultaneously a documentarian, a fantasist, and a polemicist, and the three modes were not always separable.

Pliny the Younger wrote two letters to the historian Tacitus describing the eruption of Vesuvius in 79 AD, and they are the only eyewitness account of one of the most significant natural disasters in recorded history. Pliny was seventeen years old when the eruption occurred. He watched from Misenum, across the Bay of Naples, as the cloud rose from the mountain. His uncle, Pliny the Elder — the naturalist and admiral who commanded the fleet at Misenum — sailed toward the eruption and died in it. The younger Pliny stayed behind, survived, and thirty years later wrote the letters that documented what he had seen with a clarity and precision that would have done credit to a trained scientist.

Paul W.S. Anderson’s Pompeii is not a film about the eruption of Vesuvius. It is a film about a slave-turned-gladiator and a merchant’s daughter whose love is thwarted by a corrupt Roman senator, and the eruption of Vesuvius happens to provide the third act. The volcano is plot device rather than subject. This is a reasonable choice for a commercial action film built on a historical catastrophe; it is not the choice that a serious engagement with Pompeii’s destruction would have made.

On the morning of August 24, 79 AD — though some scholars now argue for a date in October based on pomegranate seeds and autumn clothing found in the excavations — Mount Vesuvius began its eruption. By the following morning, the city of Pompeii was buried under four to six meters of volcanic ash and pumice. Approximately eleven thousand people lived there. Somewhere between two and three thousand did not escape. The volcano that killed them preserved them, and what it preserved has told us more about ordinary Roman life than any literary source.

Robert Graves published I, Claudius in 1934, followed immediately by its sequel Claudius the God, and the two novels together constitute the most successful fictional treatment of Roman history in any language. They have never been out of print. They were the basis for the BBC television series that remains the finest dramatization of Roman history ever made. They are cited by historians as substantially accurate in their broad outlines while being recognized as works of fiction that invented freely within the framework the sources provided. They are also, simply, very good novels — constructed with the discipline of a scholar and the freedom of a storyteller.

Ninety percent of the people in the Roman Empire worked the land. This is the number that most discussions of Rome skip past in their attention to the legions and the Colosseum and the philosophical schools, but it is the number that actually determined the empire’s possibilities. Everything else — the armies, the cities, the building programs, the literary culture — was built on the agricultural surplus generated by the rural majority that never appears in the histories because it was not writing them. Roman civilization was an agricultural civilization with sophisticated urban superstructure, and understanding the agriculture is understanding the base on which everything else rested.

The augurs were among the most important religious officials in Rome, and their function was specific: they observed and interpreted signs — auspices — that indicated whether the gods approved of a proposed action. Before a general led his army into battle, before a magistrate held a public assembly, before a colony was founded or a treaty ratified, the auspices were taken. A favorable sign meant the action could proceed. An unfavorable sign meant it could not — at least not on that day, in that form. The political implications of this system were considerable, and the Romans who operated it were not naive about the opportunities it created.

The popular image of Roman battlefield tactics consists largely of the testudo — the tortoise formation with interlocked shields — and the general impression of disciplined ranks advancing steadily into contact. Both elements are real but both are partial: the testudo was a specialized approach-to-wall technique rather than a general battle formation, and Roman battlefield practice was considerably more sophisticated than a mental image of advancing shield walls suggests. The Roman military system’s genius was not in any single tactical innovation but in the combination of flexible unit organization, standardized training, and the operational discipline that allowed the manipulation of formations under combat conditions that destroyed most ancient armies’ capacity for controlled maneuver.

Romans played games everywhere. Game boards scratched into the steps of the Colosseum, carved into the pavements of the Roman Forum, incised into the floors of military barracks from Hadrian’s Wall to the Syrian desert — the physical evidence for Roman gaming culture is distributed across every context where Romans spent time waiting, resting, or socializing. The games themselves ranged from dice games requiring no equipment beyond three cubes of bone or ivory to board games of genuine strategic complexity, and they were played by everyone: soldiers, merchants, slaves, emperors. Claudius was reportedly so devoted to dice games that he designed a special board for playing in his carriage. Augustus played board games regularly. The imperial dignity was not considered incompatible with sitting across a game board from someone.