In the midst of these stirring and threatening times a powerful leader was wanted. A deputation was sent to Geneva, to entreat Knox to return; and on May 2nd, 1559, he arrived at Leith. The news of his arrival fell like a thunderbolt on the papal party. A royal proclamation was immediately issued, declaring Knox a rebel and an outlaw. But these proclamations were now little heeded. Chancing to pass through Perth soon after, he preached one of his vehement sermons against the idolatry of the mass, and the worship of images. The people were ripe for such a discourse, and greatly moved by it, but quietly dispersed when it was over. A priest, remaining behind, to show his contempt for the doctrine which had just been delivered, uncovered a rich altar-piece, decorated with images, began to say mass. A boy standing near, shouted, "Idolatry!" The priest in anger struck the boy; and he retaliated by throwing a stone, which, missing the priest, broke one of the images. A few idle persons who were loitering in the church, sympathized with the boy, and in the course of a few moments, the altar, images, crucifixes, and all the church ornaments were torn down and trampled under foot. The noise soon collected a mob; the excitement became great, and some one shouted, "To the monasteries;" and in a short time the monasteries of the Black and Gray Friars were in ruins. The excited mob next bent their way to the abbey of the Charterhouse; and soon nothing was left of that magnificent structure but the bare walls. The magistrates of the town and the preachers hastened to the scene of the riot as soon as they heard of it, but neither the persuasion of the one nor the authority of the other could calm the tempest.