What powers and secrets do relics hide in medieval Europe? How did these sacred objects shape the creation of the West? At a time when faith and power were inseparably intertwined, these pages explore the role of the remains of saints and martyrs, such as the bones of St. James in Hispania, the shroud of Turin, and the sacred cup of Joseph of Arimathea in England. These symbols not only conferred prestige, but also legitimacy and authority to those who possessed them. This book delves into the struggles and strategies of European kingdoms to control these venerated relics, revealing how the cult of objects such as the sacred spear that pierced the body of Christ and the remains of Mary Magdalene in France consolidated not only faith, but also the identity and political power of an entire region. Each chapter reveals the function of these treasures as true linchpins of medieval geopolitics, generating alliances and rivalries that defined the destiny of Europe. Relics redefines the Middle Ages as a period of intense struggle and aspiration, where sacred remains played a pivotal role in the creation of a united Europe and the development of Western culture. A fascinating journey into the heart of the symbols that forged our history.