But though during the lifetime of Placidia Italy was free from foreign invasion, the decay of the western empire, of what had been the western empire, was by no means arrested; on the contrary, Britain, Gaul, Spain, and Africa were finally lost.  Two appalling catastrophes mark her reign, the Vandal invasion of the province of Africa and the ever growing cloud of Huns upon the north-eastern frontiers.

[Illustration:  THE APSE OF S. GIOVANNI EVANGELISTA]

Placidia’s two chief ministers were Boniface and Aetius, either of whom, according to Procopius, “had the other not been his contemporary, might truly have been called the last of the Romans.”  Their simultaneous appearance, however, finally destroyed all hope of an immediate resurrection of civilisation in the West.  For Boniface, whose “one great object was the deliverance of Africa from all sorts of barbarians,” betrayed Africa to the Vandals, and to this he was led by the rivalry and intrigue of Aetius who, on the other hand, must always be remembered for his heroic and glorious victory over Attila at Chalons which delivered Gaul from the worst deluge of all—­that of the Huns.

The truth would seem to be that while corruption of every sort, and especially political corruption, was destroying the empire, the importance of Christianity was vastly increasing.  The great quarrel was really that between Catholicism and heresy.  This was a living issue while the cause of the empire as a political entity was already dead.  Placidia certainly eagerly considered all sorts of ecclesiastical problems and provided and legislated for their solution.  We do not find her seeking the advice and offensive and defensive alliance of Constantinople for the restoration of her provinces.  It might seem almost as though the mind of her time was unable to fix itself upon the vast political and economic problem that now for many generations had demanded a solution in vain.  No one seems to have cared in any fundamental way, or even to have been aware, that the empire as a great state was gradually being ruined, was indeed already in full decadence—­a thing to despair of.  That is the curious thing—­no one seems to have despaired.  On the other hand, every one was keenly interested in the religious controversy of the time which, because we cannot fully understand that time, seems to us so futile.  But it is only what is in the mind that is fundamentally important to man, and that will force him to action.  The council of Ephesus which destroyed Nestorius in 431, the council of Chalcedon which condemned Dioscorus in 451, seemed to be the important things, and one day we may come to think again, that on those great decisions, and not on the material defence, both military and economic, of the West, depended the future of the world.  If this be so, it would at least explain the hopeless variance of East and West, which, almost equally concerned in the material problem, were by no means at one in philosophy.