A Capital Without Its Emperor

For 45 years after Constantine the Great’s triumph in 312 AD, the people of Rome—once the beating heart of an empire—had not seen their emperor. By 357 AD, when Constantius II finally marched through its gates, Rome’s 1,110-year legacy as the imperial capital had been reduced to a ceremonial backdrop. The city that once dictated the fate of nations now served merely as a stage for the vanity of an absent ruler. This paradox frames one of late antiquity’s most revealing moments: an emperor’s awkward homecoming to a city that no longer needed him.

The Soldier-Historian’s Lens

Our primary witness is Ammianus Marcellinus, a Greek-born Roman officer whose firsthand account pierces the pomp of Constantius’ visit. Born around 330 AD in Antioch, Ammianus abandoned his city’s mercantile traditions for military service, rising to the staff of General Ursicinus. After decades on the Danube and Euphrates frontiers, he retired to write a sequel to Tacitus’ histories—a decision that gifted posterity with an unflinching view of Rome’s decline.

His Res Gestae (surviving from 353–378 AD) offers something rare: a soldier’s Latin prose dissecting imperial theater. Though Greek was his mother tongue, Ammianus consciously emulated Tacitus’ style, blending military terseness with aristocratic education. This duality makes his description of Constantius’ 357 triumph particularly damning—a conqueror’s parade without conquest.

The Empty Spectacle

Constantius’ procession was a masterpiece of misdirection. As Ammianus notes, the emperor celebrated not a foreign victory but the suppression of Magnentius’ rebellion—a civil war that left Romans killing Romans. The lavish parade stretching 130 km from Rome’s walls featured:

– A gem-encrusted golden chariot, its purple banners writhing “like serpents”
– Persian-clad cavalry resembling “bronze statues by Praxiteles”
– An emperor frozen in studied majesty, “never spitting, wiping his nose, or moving a finger”

The theatrics betrayed insecurity. Constantius’ rigid posture—head bowed only to clear arches—mirrored his governance: isolated, inflexible, and desperate to project divinity. When his axle broke mid-procession, he remained statue-still, prioritizing image over practicality.

Rome’s Silent Rebuke

The city itself became Constantius’ unwitting critic. As his entourage passed through the Forum, the weight of history loomed:

– Trajan’s Column’s spiral reliefs chronicling genuine conquests
– The Colosseum’s 50,000-seat grandeur
– The Pantheon’s dome “kissing the heavens”

Here, the emperor’s planned equestrian statue (a feeble echo of Trajan’s monument) drew biting satire from Ormisda, an exiled Persian prince: “First build stables worthy of this square, so your horse may prance properly.” The quip exposed Constantius’ cultural illiteracy—a ruler who misunderstood Rome’s republican legacy of public benefaction.

Legacy in Stone

Compelled to contribute, Constantius erected an obelisk at the Circus Maximus—a hand-me-down from his father’s unfinished Constantinople projects. Placed beside Augustus’ original Egyptian trophy, it symbolized imperial decline: where Augustus seized obelisks as war spoils, Constantius recycled leftovers. Today, these stones tell parallel stories—one in Piazza del Popolo, the other at St. John Lateran—marking the gap between empire-builders and caretakers.

The Twilight of the Eternal City

Constantius’ 30-day stay revealed Rome’s paradoxical status: architecturally magnificent but politically obsolete. His “triumph” accelerated trends begun decades earlier:

– The Senate’s groveling deference showed how Diocletian’s tetrarchy had neutered old institutions
– Military priorities now centered on frontier capitals like Milan and Antioch
– Imperial architecture shifted from public spaces (baths, forums) to vanity projects

Yet in his rare moment of awe—gazing at Trajan’s Forum—even Constantius seemed to grasp that no obelisk could measure against republican monuments built for citizens rather than over them.

Epilogue: The Unraveling

The emperor’s rushed departure for the Danube underscored the hollowness of his triumph. Meanwhile, his cousin Julian—stationed in Gaul—was forging genuine bonds with troops through shared campaigns. Ammianus’ account foreshadows their coming clash: one emperor playing conqueror in Rome’s ruins, another becoming one on the battlefield.

Rome’s lesson echoes across empires: when rulers confuse pageantry for power, even obelisks become gravestones.