God's War offers a sweeping new vision of one of history's most astounding events: the Crusades.

From 1096 to 1500, European Christians fought to recreate the Middle East, Muslim Spain, and the pagan Baltic in the image of their God. The Crusades are perhaps both the most familiar and most misunderstood phenomena of the medieval world, and here Christopher Tyerman seeks to recreate, from the ground up, the centuries of violence committed as an act of religious devotion.

The result is a stunning reinterpretation of the Crusades, revealed as both bloody political acts and a manifestation of a growing Christian communal identity. Tyerman uncovers a system of belief bound by aggression, paranoia, and wishful thinking, and a culture founded on war as an expression of worship, social discipline, and Christian charity.

This astonishing historical narrative is imbued with figures that have become legends--Saladin, Richard the Lionheart, Philip Augustus. But Tyerman also delves beyond these leaders to examine the thousands and thousands of Christian men--from Knights Templars to mercenaries to peasants--who, in the name of their Savior, abandoned their homes to conquer distant and alien lands, as well as the countless people who defended their soil and eventually turned these invaders back. With bold analysis, Tyerman explicates the contradictory mix of genuine piety, military ferocity, and plain greed that motivated generations of Crusaders. He also offers unique insight into the maturation of a militant Christianity that defined Europe's identity and that has forever influenced the cyclical antagonisms between the Christian and Muslim worlds.

Drawing on all of the most recent scholarship, and told with great verve and authority, God's War is the definitive account of a fascinating and horrifying story that continues to haunt our contemporary world.

Christopher Tyerman is Lecturer in Medieval History at Hertford College and New College, University of Oxford.