It proved easy to adapt the ideology and rhetoric of the Holy Land to internal religious and political conflicts within Christendom and to frontier wars with non-Christians. ‘Crusades in the west’ charts conflict directed inwardly within Europe. The Children's Crusade in the summer of 1212 consisted of two outbursts of popular religious enthusiasm which arose out of an atmosphere of crisis. This feeling of crisis came from perceived threats to Christendom from Muslims in the Holy Land, the Moors in Spain, and heretics in southern France. These marches were paralleled in the Shepherds's Crusade of 1251. When did this period of crusading end, and what ended it?