That some social gains may be correlative with great historic evils is perhaps best seen in the case of the Crusades organized by the Church against the Saracens in Palestine. These campaigns were first conceived in the interests of the papal power; and as early as 999 Pope Sylvester II (Gerbert), who had been anti-papal before his elevation, sent a letter through Europe appealing for united action on behalf of the Church of Jerusalem. There was no response. In 1074 Gregory VII strove hard to the same end, seeing in a conquest of the Turks a means to extend his power over the Eastern Church. Not, however, till Europe was full of tales of the cruelties wrought by the new Eastern power, the Turks, against Christian pilgrims--a marked change from the comparative tolerance of the Caliphs--was it possible to begin a vast crusading movement among all classes, aiming at the recovery of the empty sepulchre from which the Christ had risen. To this movement Pope Urban II zealously lent himself, backing up the wild appeal of Peter the Hermit (1094) with the fatal bribe of indulgences. The first effect (1096) was to collect several immense and almost formless mobs of men and women who by all accounts were in the main the refuse of Europe. "That the vast majority looked upon their vow as a licence for the commission of any sin there can be no moral doubt." The devout exaltation of the few was submerged by the riot of the many, who began using their indulgences when they began their march, and rolled like a flood across Europe, massacring, torturing, and plundering Jews wherever they found them, and forcibly helping themselves to food where plunder was easy. Multitudes perished by the way; multitudes more were sold as slaves in Byzantium to pay for the feeding of the rest there; and of the seven thousand who reached Asiatic soil with Peter the Hermit, four thousand were slain by the Turks at Nicæa; some 300,000 thus perishing in all. Inasmuch as Europe was thus rid of a mass of its worst inhabitants, the first crusade might be said so far to have wrought indirect good; but the claim is hardly one to be pushed on religious grounds.