Book excerpt: The second of a projected six volumes, this carries the story of the building of a Christian civilization in Europe from the conversion of Roman Emperor Constantine in the fourth century to the end of the First Crusade. Christ and His Church remain at the center of the story and the key to judging the significance and character of the events described. However, this is more than a history of the Church; it is a political and religious history of Christendom as shaped by the Church - by lay men and women as well as Popes, bishops, priests, monks and nuns - during eight dramatic centuries when Rome fell, Muslims and barbarians attacked Christian Europe, and a new civilization was born.