By this time the emperor was irritated and exhausted by the continual wars thrust on him by the Papacy. He had enjoyed no peace since the day (June 24, 1243) when Sinibaldo de Fieschi ascended the Chair of St. Peter as Pope Innocent IV. This pontiff had pronounced his deposition at the Council of Lyons in 1245. He had then secretly excited many conspiracies against him, and attempted more or less to ensure their success. The emperor had been led to suspect his most devoted friend and secretary, Pier delle Vigne, of complicity in one of these plots. Accordingly this faithful servant was thrown into the tower of San Miniato al Tedesco, condemned to lose his eyes, and then transferred to another prison in Pisa, where he dashed out his brains against the wall. Frederic's spirit was alternately cowed and irritated by the hostility he encountered; for, with all his philosophy and unbelief, he greatly dreaded the thunders of the Vatican. He sought reconciliation with the Pope, wished to return to the East to fight the infidels; and Innocent chose that moment to rouse all the Guelph cities against him, thus again forcing him to fly to arms to support the Ghibelline cause and maintain his own sway over Italy. This he was unable to effect without recurring, as we have seen, to incredible excesses of violence, which naturally increased the number of his enemies on all sides. The Guelphs of Germany had already refused to acknowledge the authority of his son Corrado, whom he had sent as his representative. The army commanded by the emperor in person had been routed at Parma. All the Guelph cities of Romagna, with Bölogna at their head, marched a powerful force against the Ghibellines under King Enzo, another of Frederic's natural sons, and defeated them at the battle of Fossalta on May 26, 1249. Enzo himself was captured and carried in triumph to Bologna, where he remained a prisoner till his death in 1271. But the emperor did not live long enough to feel this last blow. On December 13, 1250, he ceased to breathe in a castle near Lucera in Apulia, and his death completed the downfall of the Ghibelline party in Florence and throughout Italy. For religious hatred was now combined with political enmity against this party. Not only because the Ghibellines combated the Pope, but still more, because the various heresies gradually spreading through Italy found many followers in their ranks, in consequence of frequent marks of tolerance and favour received from the emperor. The heretical poison now slowly infecting the Italian social body was a grave anxiety to the Popes. The Albigenses had first roused attention and found adherents in Provence, where native bards had devoted their talents to attacking the Roman Court. But the religious orders of St. Francis and St. Dominic were bent on crushing the new creed. Innocent III. had founded the Holy Inquisition for the same purpose, and St. Dominic, at the head of mobs thirsting for heretic blood, had ordained the