ROME — “If a man were called to fix the period in the history of the world during which the condition of the human race was most happy and prosperous, he would without hesitation, name that which elapsed from the death of Domitian to the accession of Commodus,” Edward Gibbon wrote in “Decline and Fall of the Roman Empire.”....

At first glance, by its very title “The Age of Equilibrium, 98-180 A.D.: Trajan, Hadrian, Antoninus Pius, Marcus Aurelius,” the third in a series of exhibitions on art and society in ancient Rome at the Capitoline Museums, seems to be endorsing this traditional historical assessment that stretches from Pliny the Younger through Machiavelli and Gibbon into modern times.

But a strength of this latest show, curated by Eugenio La Rocca and Claudio Parisi Presicce with Annalisa Monaco, and especially of its catalog, is that, while achievements are recognized, darker aspects are not whitewashed and the dominant role played by propaganda in public art of the era is highlighted....

The Age of Equilibrium, 98-180 A.D. Trajan, Hadrian, Antoninus Pius, Marcus Aurelius. Capitoline Museums, Rome. Through May 5.