According to tradition, it all began when Pope Urban II called on the knights of Europe to liberate Jerusalem from Islam. But was the real catalyst located somewhere far to the east of Rome?

Peter Frankopan challenges established interpretations of a millennium, shifting the focus to Constantinople and the Byzantine Empire. The First Crusade shaped the fates of the Middle Ages. It established the common identity of European knighthood, unwaveringly grounded in the Christian faith.

It influenced the behavior of knights, with piety and duty emerging as valuable personal virtues, celebrated in poems and prose, songs, and works of art. It idealized the notion of the pious knight fighting for God.

It established the Pope as a leader of not just spiritual significance but also political weight. It provided a common purpose to the Western dominions, creating a framework in which the defense of the Church was not only desired but also enforced. With the First Crusade, the ideas and structures were born that shaped Europe until the Reformation.