At first it was Gaul that was to be plundered; but there, as we know, the wild beast was met by Aetius who defeated him at the battle of Chalons and thus saved the western provinces. But that victory was not followed up. Attila and his vast army were allowed to retreat; and though Gaul was saved, Italy lay at their mercy. That was in 451. Attila retreated into Pannonia, and prepared for a new raid in the following year.
He came, as Alaric had done, through the Julian Alps; and before spring had gone Aquileia was not, Concordia was utterly destroyed, Altinum became nothing. Nor have these cities ever lived again; out of their ruin Venice sprang in the midst of the lagoons. All the Cisalpine plain north of the Po was in Attila's hands; Vicenza, Verona, Brescia, Bergamo, Pavia, even Milan opened their gates. No defence was offered, they saved themselves alive. And southward, over the Po, between the mountains and the sea, the gate which Ravenna held stood open wide. Italy without defence lay at the mercy of the Asiatic invader.
Without defence! Valentinian and his court were in Rome; no one armed and ready waited in impregnable Ravenna to break the Hun as with a hammer when he should venture to take the road through the narrow pass between the mountains and the sea. The great defence was not to be held; the road, as once before, lay open and unguarded. In this moment, one of the greatest crises in the history of Europe, suddenly, and without warning, the reality of that age, which had changed so imperceptibly, was revealed. The material civilisation and defence of the empire were, at least as organised things, seen to be dead; its spiritual virility and splendour were about to be made manifest.
For it was not any emperor or great soldier at the head of an army that faced Attila by the Mincio on the Cisalpine plain and saved Italy, but an old and unarmed man, alone and defenceless. Our saviour was pope Leo the Great; but above him, in the sky, the Hun perceived the mighty figures, overshadowing all that world, of S. Peter and S. Paul, and his eyes dazzled, he bowed his head. "What," he asked himself, "if I conquer like Alaric only to die as he did?" He yielded and consented to retreat, Italy was saved. The new emperor, the true head and champion of the new civilisation that was to arise out of all this confusion, had declared himself. It was the pope.
There, it might seem, we have the truth at last, the explanation, perhaps, of all the extraordinary ennui and neglect that had made such an invasion as that of Alaric, as that of Radagaisus, as this of Attila, possible. For it is only what is in the mind that is of any importance. The empire rightly understood was not about to die, but to change into a new spiritual kingdom in the hearts of men; and there, in the place of the emperor, would sit God's Vicegerent, till in the fullness of time the material empire should be re-established and that Vicegerent should place the imperial crown once more upon a merely royal head. The force of the old empire had always lain in wholly material things and its excuse had been its material success; but it was a servile state, and after the advent of Christianity it was inevitable that it should change or perish. It changed. The force of the new empire was to be so completely spiritual that to-day we can scarcely understand it. Upon the banks of the Mincio it declared itself; and when, twenty-three years later, Odoacer the barbarian deposed Romulus Augustulus and made himself king of Italy, the true champion of all that Latin genius had established was already enthroned in Rome; but the throne was Peter's, and men called him not Emperor but Father.
Those twenty-three years, so brief a period, are, as we might imagine, full of confusion and strange barbarian voices.
After Leo had turned him back from Italy there by the Mincio, Attila retreated again into Pannonia, but he still insisted "on this point above all, that Honoria, the sister of the emperor and the daughter of the Augusta Placidia, should be sent to him with the portion of the royal wealth which was her due; and he threatened that unless this were done he would lay upon Italy a far heavier punishment than any which it had yet borne." But within a year Attila was dead in a barbaric marriage-bed by the Danube, and his empire destroyed. And as for Honoria we know no more of her, she disappears from history, though tradition has it that she spent the rest of her life in a convent in southern Italy.
The two heroes of the Hunnish deluge in the West were Aetius, the great general who broke Attila upon the plain of Chalons, and Leo the pope surnamed the Great. Aetius had been unable to persuade his victorious troops to march to the defence of Italy, and in this again we see the growing failure of the imperial idea; but he was a great soldier, and certainly the greatest minister that Valentinian III. could boast. Nevertheless, after the death of Attila he seemed to the emperor both dangerous and useless; dangerous because, like Stilicho, he thought of the empire for his son, and useless because Valentinian had recently placed his confidence in another, the eunuch Heraclius. Just as Honorius contrived the murder of Stilicho, so did Valentinian contrive to rid himself of Aetius, and with his own hand, for Valentinian stabbed him himself in his palace on the Palatine Hill in Rome, towards the end of 454. Six months, however, had not gone by when Aetius was avenged and Valentinian lay dead in the Campus Martius stabbed by two soldiers of barbarian origin. Beside him, dead too, lay the eunuch Heraclius. This was the vengeance of the friends of Aetius, and of him who was to be emperor, Petronius Maximus, whose wife Valentinian had ravished.
With Valentinian III., who had no children, the great line of Theodosius came to an end both in the East and in the West, for Pulcheria had died in 453. In Constantinople Marcian continued to rule till 457, when he was succeeded by Leo I. the Thracian. In Rome he who had so signally avenged himself, Petronius Maximus, a senator, sixty years of age, reigned during seventy days in which he was rather a prisoner than a monarch. During those seventy days, whether moved by lust or revenge we know not, he attempted to make the widow of Valentinian his wife. This brought all down, for Eudoxia, without a friend in the world, followed the fatal example of Honoria and called in the Vandal to her assistance. And when Genseric was on his way to answer her from Carthage, the terrified City, by the hands of the imperial servants and the soldiers, tore the emperor limb from limb and flung what remained into the Tiber so that even burial was denied him. But the Vandal came on, and in spite of Leo, as we know, sacked the City and departed—to lose the mighty booty in the midst of the sea.
What are we to say of the years which follow, and what are we to say of those ghostly figures, which hover, always uncertainly and briefly, about the imperial throne after the assassination of Valentinian III. and the second sack of the City? There was Avitus the Gaul (455-456), Majorian (457-461), Libius Severus (461-465), Anthemius (467-472), Olybrius (472), Glycerius (473-474), Julius Nepos (474-475), and at last the pitiful boy Romulus Augustulus (475-476). Nothing can be said of them; they are less than shadows, and their empire, the material empire they represented, was no longer conscious of itself, was no longer a reality, but an hallucination, haunting the mind. It is true that the chief seat of their government, if government it can be called, was Ravenna, and that the city is concerned with most of the incidents of those vague and confused years; the proclamations of Majorian, of Severus, of Glycerius, and of Romulus Augustulus, the abdication of the last and the fight in the pinewood in which his uncle Paulus was broken and Odoacer made himself master. But they are, for the most part, the years of Ricimer the patrician, for they are full of his puppets.