But troubles very soon began for the new-comers. The German party in Moravia were resentful at the introduction into the churches of what they considered a barbarous language; and they saw danger to their power, both in the adoption of a ritual which was understood by the people, and in the assertion of an episcopal authority which claimed to be independent of the German bishops. Nor was it only by foreigners that the influence of Cyril and Methodius was endangered; an opposition was roused even among the Moravians themselves. Svatopluk, the nephew and rival of Rostislav, seems to have accepted some kind of nominal Christianity, but unaccompanied by any change of life, or even by any great reverence for the externals of worship; and he opposed the new apostles of the Slavs with the greatest fierceness. The opposition of this ambitious prince no doubt arose at first from his desire to pose as the champion of the German party, who were undermining his uncle’s authority. According to one story he had already attempted to poison Rostislav, and having failed in that purpose he conspired with the Emperor Louis against him, made him prisoner, and sent him off to the Imperial Court to be tried. Louis threw Rostislav into prison, and put out his eyes. But Svatopluk, though he succeeded in seizing the Dukedom, did not long retain the confidence of the Emperor or the German party. He, in his turn, was deposed and thrown into prison. Then the Moravians rose against the Franks, under a man named Slavomir, who, according to one story, was a pupil of Methodius. The Emperor thereupon set Svatopluk free, and sent him at the head of an army to suppress the new rising. Svatopluk betrayed his soldiers to his countrymen, destroyed the German army, and once more became Duke of Moravia. He now felt it impossible any longer to pose as the champion of the German party; and he had married the sister of Duke Bor̆ivoj, of Bohemia, in order to strengthen the alliance of the Slavs against the Franks. As a part of his new policy, he was forced, for a time, to encourage the movement of Methodius; and it was during this period that the archbishop or one of his followers converted and baptised Bor̆ivoj, and induced him to found two churches in memory of St. Clement of Rome, whose remains Cyril had discovered in his expedition to the Chazars.