The Spread of Christianity By facebooker_1148193712201013 Period: 622 to 632 Conquests of Mohammed Period: 632 to 661 Conquests of the First Four Caliphs Period: 661 to 900 Omayyad and Abbasid Conquests Period: 1096 to 1099 The First Crusade Period: 1147 to 1149 The Second Crusade