At more than thirty-one years (1903-1935), Cardinal Bourne's is the longest reign of any Archbishop of Westminster. Today, with the possible exception of his turbulent relationship with Bishop Amigo of Southwark, Bourne is virtually unknown. That obscurity is unmerited. His time at Westminster covered some of the most momentous events of the modern English Catholic Church: the Education Question, Modernism, the First World War, the Irish Troubles and Treaty, the emergence of the Labour Party, the General Strike, the growing menace of the European dictators and the stirrings of ecumenism and Catholic social policy. By temperament and preference, Bourne played a quiet role in all these issues, but it was neither passive nor negligible. In difficult times, he led the Catholic Church conscientiously and well. This biography provides a long overdue and comprehensive reassessment of one of the most important figures of twentieth-century Church history.