Led in 1251, by Jacob of Hungary, the followers of whom became known as the ‘pastoureaux’ and began to spread though Central Europe just as news reached her villages and towns that the Seventh Crusade had failed. Jacob, a former monk gathered a following by preaching a new sort of trip to the Holy Land. Plus, he said he’d had a vision of the Virgin Mary surrounded by angels, and he even had a letter (from her?) to prove it – a sort of angelic summons to poor shepherds, farmers and simple folk everywhere to do what they could to free the Holy Sepulchre. After all, clearly the knights, nobles and priestly classes of Christendom weren’t doing such a bang up job of leadership – why not give the trades-people a crack at the infidels, as with the The Childrens Crusade (1212) and The Peasants Crusade (1069).
    That, at least, was the general argument of Jacob’s preaching. A sort of populist pilgrimage and pillage was primarily the plan. Quite quickly all sorts of people, including children and as many criminals arrived armed with pitchforks, hatchets, knives and clubs to join this ‘crusade’ – it had quickly become an army many thousands strong. Jacob had already been rumored to be able to heal the sick and part water, so people were confident things would go well and they would be provided for.
    Things went off the rails quickly as the masses gathered. People went hungry, then they got cranky. As with the Peasants Crusade, the logistics were poorly executed. The leaders of the movement began to criticize Church officials, as had been the case among some previous similar movements. Soon Jacob led the masses through France. In Tours, his soldiers whipped friars in the street, and soon they were stringing up priests and monks. When the throng arrived in Bourges, the swell of shepherds headed straight for the Jewish Quarter. This was the last straw, and local knights soon marched in to put down the insurgents, and Jacob was slain in the street. After his death, many officials circulated the theory that the Sultan of Arabia had secretly been Jacob’s true master, and his real goal was to lure the unwary to the desert and subvert authority in Christendom.

See Norman Cohn’s The Pursuit of the Millennium: Revolutionary Millenarians and Mystical Anarchists of the Middle Ages (NY: Oxford, 1970) p. 94-101.