The History of the Decline and Fall of the Roman Empire

The popular image of Rome's fall is a wall of Goths and Vandals crashing over the frontier. Gibbon does narrate the sack of Rome by Alaric's Goths in 410, and the deposition of the last Western emperor, the boy Romulus Augustulus, in 476. But he is careful to insist that the barbarians did not so much conquer the empire as move into a house that was already emptying out. The interesting question, for him, is why the Roman world could no longer keep them out.

Part of the answer is military. Over the centuries, the legions stopped being armies of Roman citizens defending their own state and became increasingly staffed by the very peoples they were meant to repel. Rome hired Germanic warriors, settled them inside the frontiers, and came to depend on them. The distinction between the empire's soldiers and its enemies blurred until it barely existed. When a general like Stilicho, himself of Vandal descent, effectively ran the Western army, the machinery of defense had already changed hands.

The most controversial thread in the whole work is Gibbon's treatment of Christianity, and it earned him furious replies in his own lifetime. He does not argue that the new religion single-handedly toppled Rome — that would be too crude for him. What he argues, in his cool and needling way, is that the rise of the church changed where Romans directed their loyalty, their money, and their energy, and that some of that change came at the expense of the state that had once absorbed all of it.

His case runs along several lines. A civilization that had prized civic virtue and public service, he suggests, increasingly prized salvation and the life to come. Wealth that might have flowed to the treasury or to public works flowed instead to monasteries and clergy. Talented men who might have governed provinces or led armies withdrew into contemplation. And the bitter doctrinal quarrels of the early church — over the nature of Christ, over orthodoxy and heresy — consumed the attention of emperors and split cities against themselves at moments when unity mattered.

Here Gibbon steps back, and the step-back is built into his structure. Most readers stop at 476, but he does not — three of his six volumes carry the story another thousand years, through the Eastern Empire ruled from Constantinople, what we now call Byzantium. This is the move that gives the whole work its meaning. By refusing to let the story end with the West, Gibbon turns a single fall into a study of how empires actually behave over the very long run: not dying in a day, but persisting, mutating, and slowly diminishing across centuries.

The Eastern half survived the crisis that killed the West. It kept Roman law, Roman administration, and the imperial title, even as its language became Greek and its character became something new. Gibbon follows it through the reconquests of Justinian, the shock of the Arab conquests in the seventh century, the long defense of Anatolia and the Balkans, and the slow contraction to a city and its hinterland. When the Ottoman guns finally breach the walls of Constantinople in 1453, the empire Augustus had founded finally, formally, ends — nearly a millennium after the West.

Gibbon finished the last lines of the sixth volume on the night of June 27, 1787, in a garden in Lausanne, and later wrote that he felt both joy and a strange melancholy at parting from a companion of so many years. The book he left behind runs from a young man's afternoon among the ruins of the Capitol to the Turkish cannon at the walls of Constantinople, and its through-line never wavers: the empire was not murdered from outside so much as hollowed from within, over centuries, by the very forces that had once made it strong.