"Constantine's Sword" by James Carroll is a nonfiction book that explores the history of anti-Semitism within the Catholic Church and its impact on the broader history of Western civilization. Carroll, a former Catholic priest, delves into the roots of anti-Semitism, tracing its origins to the time of Constantine the Great, the first Christian Roman emperor. He examines how anti-Semitic attitudes and policies were institutionalized within the Church and influenced political, social, and religious events throughout history, including the Crusades, the Inquisition, and the Holocaust. Carroll also reflects on his own personal journey and relationship with the Church as he grapples with the dark legacy of anti-Semitism. Through extensive research, historical analysis, and personal introspection, Carroll offers a thought-provoking and challenging exploration of the complex relationship between Christianity, anti-Semitism, and the human capacity for prejudice and intolerance. "Constantine's Sword" sheds light on a controversial and often overlooked aspect of history and encourages readers to critically examine the role of religion and its impact on society.