Jacques-Louis David completed The Oath of the Horatii in Rome in 1784 and exhibited it at the Paris Salon the following year. It stopped the room then. It still stops rooms now — visible here on the deep terracotta wall of the Louvre’s Denon Wing, large enough to command the gallery from any angle, the three brothers extending their sword arms toward their father in a gesture that has not lost its charge in two and a half centuries.

Jacques-Louis David painted the Oath of the Horatii in 1784, five years before the French Revolution, and the painting arrived in Paris as a political event rather than simply an aesthetic one. Three Roman brothers swear to their father to fight to the death for Rome against the rival city of Alba Longa, their arms extended toward the swords their father holds, their posture rigid with civic resolution. Behind them, the women of the family — who are connected by marriage to the enemy side — collapse in grief that the oath requires be subordinated to duty. The painting is a lecture on republican virtue delivered at the exact moment when the French intelligentsia was developing the vocabulary of republican revolution, and it was received as such.

The Roman triumph — the procession through the city in which a victorious general displayed his captives and the spoils of conquest before depositing the latter in the treasury and offering thanks at the temple of Jupiter Capitolinus — was the most spectacular public ritual of the Roman world, and its visual representation has served as propaganda for European rulers from the Renaissance through the nineteenth century. The triumph’s logic — the hero returns, the enemy is displayed, the city is made to feel the extent of its power — was available for appropriation by any ruler who needed to communicate the same things, and the painters who rendered ancient triumphs for modern patrons understood they were serving both historical documentation and political argument simultaneously.