- The County of Portugal is established for the second time by Count Henry of Burgundy.
- Pembroke Castle is built in Wales.
- The cathedral in Valence, France is consecrated.
- Coloman becomes King of Hungary.
- Overpopulation in France, according to Pope Urban II.
- March: Byzantine emperor Alexius I Comnenus sends ambassadors to Pope Urban II, at the Council of Piacenza, to discuss sending mercenaries against the Seljuk Turks.
- November 19: The Council of Clermont begins. The council is called by Pope Urban II to discuss sending the First Crusade to the Holy Land.
- November 27: Pope Urban II preaches the First Crusade at the Council of Clermont; Peter the Hermit begins to preach throughout France.
- November 28: On the last day of the Council of Clermont, Pope Urban II appoints Bishop Adhemar of Le Puy and Count Raymond IV of Toulouse to lead the First Crusade to the Holy Land.