The Council Of Piacenza Asks Pope Urban II For Aid Against The Turks

The Council of Clermont was a mixed synod of ecclesiastics and laymen of the Catholic Church, which was held from November 18 to November 28, 1095 at Clermont, France. Pope Urban II's speech on November 27 was the starting point of the First Crusade.

http://en.wikipedia.org/wiki/Council_of_Clermont