The dramatic story behind an extraordinary transformation: the reconciliation between Europe’s Protestants and Catholics, and the emergence of a new era of Christian collaboration.

For centuries, Europe’s Catholics and Protestants were bitter rivals, each group blaming the other for violence and alleged moral decline. Yet starting in the 1930s, they swiftly made peace, abandoning old stereotypes and even forming joint political parties and social organizations. Why did these erstwhile adversaries suddenly start cooperating, and what were the consequences?

A groundbreaking study, The End of the Schism overturns conventional wisdom about this revolutionary change. Udi Greenberg shows that ecumenism did not grow out of mutual tolerance. Rather, Christian thinkers and politicians on both sides of the Catholic-Protestant divide came together to contain what they considered growing threats to Christian life: socialism, feminism, and Afro-Asian liberation movements. This project of interconfessional peacemaking accelerated with the rise of the Nazis, whose call for religious unity sparked intense debates among Christian denominations about their relationships with one another. Their rapprochement culminated in the unfolding of the Cold War and decolonization, when Catholic and Protestant authorities formally declared each other “brethren in faith.”

The End of the Schism makes clear the enormous consequences of the ecumenical revolution. By working together, Catholics and Protestants were able to design Europe’s economic policies, regulate its sexual practices, and deeply shape its postwar relationship with the Global South. As confessional attachments in Europe have weakened, this coalition of Christians has only grown more cohesive, leveraging their alliance to maintain influence across a politically fractured continent.