On 15 August 1096 the armies of the First Crusade set out from Europe to deliver Jerusalem from the occupying forces of Islamic Turks. Championed by Peter the Hermit in 1093, Pope Urban II had sanctioned the crusade at the Council of Clermont in 1095. An interesting article about the First Crusade is found at http://www.historylearningsite.co.uk/cru2.htm. Many historical sources credit Peter the Hermit as the originator of the First Crusade. However, The New Advent Online Catholic Encyclopedia disputes this. You may read this article at http://home.newadvent.org/cathen/11775b.htm.