For 10 points, name this military action in which Christians went eastward and successfully conquered Jerusalem.
Carl Erdmann's thesis is one explanation of the causes of this event. This campaign inspired a series of attacks against Jews in Speyer and Worms led by Count Emicho. Kerbogha of Mosul failed to relieve a siege in this conflict. One side in this war was massacred at Cibotus. At the Council of Piacenza, envoys of Alexius I asked for aid in what would become this action. Armies in it were led by Raymond of Toulouse, Bohemond, and Godfrey of Bouillon, while its less organized leaders included Walter the Penniless and Peter the Hermit. It was preached at the Council of Clermont in 1095 by Pope Urban II. For 10 points, name this military action in which Christians went eastward and successfully conquered Jerusalem.
Carl Erdmann's thesis is one explanation of the causes of this event.
First Crusade