This title delves into the intertwined lives of St. Anselm, the renowned theologian and Archbishop of Canterbury, and Robert of Meulan, an influential Anglo-Norman nobleman and advisor to the English crown. These two figures, representing the sacred and the secular, engaged in a lifelong adversarial relationship that spanned both Normandy and England during a pivotal period of political and ecclesiastical change. Anselm, a former abbot of Bec, came into conflict with the English monarchy over the autonomy of the church, while Robert championed the rights of the state as an advisor to multiple kings. Their disputes, particularly over the Investiture Controversy, defined a critical era in the development of English political and religious policy, revealing the tension between regnum (the realm) and sacerdotium (the church). Despite their frequent clashes, Anselm and Robert ultimately worked toward a vision of stability for the Anglo-Norman realm. While Anselm's legacy endures in the form of his theological contributions and sanctity, Robert's accomplishments are less widely remembered outside of specialized historical circles. This study aims to provide a fuller picture of both men, focusing on the political, philosophical, and personal forces that shaped their lives and legacies. Through meticulous analysis of historical sources and a synthesis of previously published research, the book illuminates how the contrasting visions of Anselm and Robert for a "right order" in the Christian kingdom ultimately converged, forming a compromise that influenced the balance of church and state for generations to come. This title is part of UC Press's Voices Revived program, which commemorates University of California Press's mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived makes high-quality, peer-reviewed scholarship accessible once again using print-on-demand technology. This title was originally published in 1987.