Council of Clermont: Urban II calls for a crusade

In March 1095, at the council of Piacenza, envoys of Emperor Alexios I asked the pope for help against the Turks, who since the 1070s had overrun most of Byzantine Asia Minor. Urban II, a former grand prior of Cluny, then travelled to France and in November held a council at Clermont in the Auvergne, attended by some three hundred clerics. Most of its business concerned church reform: it renewed the Truce of God and extended the excommunication of King Philip I of France for his marriage to Bertrade de Montfort. On 27 November Urban preached to clergy and laymen in the open air — no building, Robert the Monk explains, could hold the crowd. No text of the sermon survives; of the five later versions, that of Fulcher of Chartres, who was present, is generally considered the most reliable. In it the pope calls on those who had been robbers to become knights and promises absolution to all who die on the way or in battle; Robert the Monk, writing in 1107, adds a vivid account of Turkish atrocities, an emphasis on Jerusalem and the crowd's cry "Deus vult!" — "God wills it" — which many historians regard as coloured by the crusade's success.

Adhemar, bishop of Le Puy, is said to have been the first to take the cross: according to Baldric of Dol, he knelt before the pope in front of the whole council to ask his blessing for the journey, and Urban put him in command of the army. In a letter of December 1095 the pope fixed the departure for 15 August 1096. Through 1095 and 1096 the pope toured France, and bishops and wandering preachers such as Peter the Hermit spread the call further. Historians debate where the initiative lay: Peter Frankopan argues that the decisive impulse came from Alexios's appeal, while others stress the pope's wish to turn knightly violence outwards and to assert papal leadership during the struggle with Henry IV.