In truth, at the time the western empire fell the Catholic Church was threatened with the loss of everything which, down to the time of St. Leo, she had gained. For the triumph which Constantine's conversion had announced, for the unity of faith which her own Councils had maintained from Nicaea to Chalcedon, she seemed to have before her subjection to a terrible despotism in the East, extinction by one dominant heresy in the West. For here it was not a crowd of heresies which surrounded her, but the secular power at Rome, at Carthage, at Toulouse and Bordeaux, at Seville and Barcelona, spoke Arian. Who was to recover the Goth, the Vandal, the Burgundian, the Sueve, the Aleman, the Ruge, from that fatal error? Moreover, her bounds had receded. Saxon and Frank had largely swept away the Christian faith in their respective conquests. Who was to restore it to them? The Rome which had planted her colonies through these vast lands as so many fortresses, first of culture and afterwards of faith, was now reduced to a mere _municipium_ herself. The very senate, with whose name empire had been connected for five hundred years, at the bidding of a barbarous leader of mercenaries serving for plunder, sent back the symbols of sovereignty to the adventurer, whoever he might be, who sat by corruption or intrigue on the seat of Constantine in Nova Roma. This thought leads me to endeavour more accurately to point out the light thrown upon the Papal power by the various relations in which it stood at different times to the temporal governments with which it had to deal.