Nicholas did a greater work than Hildebrand because the times permitted him. He had to deal with the degenerate descendants of Charlemagne, not with a powerful ruler. On the other hand, court-favour and prosperity had made the leading prelates a feudal aristocracy, often arrogant and avaricious; and the monks they threatened and the priests they oppressed turned eagerly from them to the Roman court of appeal. Princes chafed at the independence of their spiritual vassals, and would depose them: bishops chafed at the interference of their suzerains, and would assert the independence of the Church. A thousand voices appealed to Rome. The fact that the _Forged Decretals_ were not made at Rome or in the interest of Rome, but by the provincial clergy in their own interest, gives us the measure of the age. And the fact that such forgeries were at once received reminds us of another favourable circumstance: the dense ignorance of the time. There was culture in places, as the contemporary work of Scotus Erigena reminds us, but to check these Papal claims one needed a knowledge of history, and the true story of the development of the Church and the Papacy, as we know it, was buried under a dense growth of legends and forgeries. Hence the dogmatic Papal conception, partly based on such documents as the _Donation of Constantine_ and the _Forged Decretals_, sank almost unchallenged into the mind of Europe, and the Pope was now enabled to dispense with the swords of princes and rely on religious threats. The letters of Nicholas splutter anathemas from beginning to end.
His first extant letter gives the Archbishop of Sens and his colleagues a stern lesson on the prestige of the Papacy, as understood by Nicholas I. The sixth letter peremptorily orders the great Hincmar of Rheims and his colleagues, in language of the simplest arrogance, to excommunicate at once, as he had directed, the Countess Ingeltrude. But within a few years Nicholas was involved in such a mesh of correspondence with offending princes and prelates that we must consider the chief causes in succession.
The Eastern Empire was then ruled by Michael the Drunkard, his mistress Eudocia, and the Emperor's tutor in vice, his uncle Bardas. This pretty trio deposed the saintly Ignatius from the See of Constantinople, and put in his place the imperial secretary Photius, one of the most accomplished scholars and least scrupulous courtiers of the East. The better clergy protested, and the court sought the support of the Pope. A glittering captain of the guards presented himself at Rome with a set of jewelled altar-vessels and, no doubt, a diplomatic account of the situation. But Nicholas at once rebuked the Emperor for his "presumptuous temerity" in deposing Ignatius without the assent of Rome, and sent legates to inquire into the matter; and he took prompt occasion to demand the restoration of Papal rights and patrimonies in the East.[148] The Eastern court must have gasped at this language. However, the Pope's legates were suborned, and a Council held at Constantinople (May, 861) confirmed the election of Photius. Nicholas was not satisfied,[149] and at length he heard the truth from Ignatius. He called a Council at Rome, ordered Michael to restore Ignatius,[150] and threatened Photius with all the anathemas in the Papal arsenal if he did not retire.