In his cell, amid silence, fasting and prayer he grew to believe himself the agent of heaven for the accomplishment of some great purpose, and he left his retreat to go on a pilgrimage. What he witnessed and suffered on the way and at Jerusalem gave to his zeal fresh determination and to his devotion the fervor of righteous indignation. His spirit was fired by the insults to Christians, his piety shocked by the profanations of the Holy Sepulchre by the barbarians and infidels. To his fevered imagination as to that of Joan of Arc there was a vision and a voice. While prostrate before the Holy Sepulchre the voice of Christ was heard, saying: "Peter, arise, hasten to proclaim the tribulation of my people; it is time my servants should receive help, and that the holy places should be delivered." He hastened to Italy and threw himself at the feet of the Pope, Urban II. With the blessing of the Pope he went forth, the preacher of an armed crusade. In imitation of Christ, when he entered Jerusalem in that last week of his life, he traveled on a mule. With crucifix in hand, feet bare, his head uncovered, his body covered with a long frock and girded with a thick cord, his appearance was an awesome spectacle. He went from city to city, from province to province, working on the piety, the superstitions and the courage of his hearers; now in churches, then in village marts and again on the public highways. He was animated and eloquent, his speech filled with vehement apostrophes and appalling descriptions. His exhortations threw the people into sobs and groans, fury and frenzy. Sympathy with the afflicted Christians took the form of furious fervor, natural bravery went out in oaths to redeem or die; religious emotions ran wild in excesses and swung like a pendulum from the lowest follies of superstition to the fiercest outbursts of fanaticism. It was during this excitement that the Emperor Alexius sent a message to Pope Urban II., appealing for aid. A council was called at Clermont in France where Peter's preaching had caused the greatest awakening. The Pope attended in person, about him gathered an immense throng of clergy, princes and laity, from France, Italy and Germany. At the tenth session of this council the Pope ascended a pulpit in the open air and preached the sacred duty of redeeming the Sepulchre of Christ from the infidels, proclaiming the certain propitiation for sin by devotion to this meritorious service.