The rise of Christianity in the 4th century CE set in motion a profound transformation of the Roman legal world. As the empire became officially Christian, new moral and ethical concerns began to reshape the law. The legal system slowly started to reflect the values of the new state religion. This episode traces the impact of Christianity on late Roman law. We examine how emperors like Constantine and Theodosius passed laws that promoted the Church, restricted pagan practices, and targeted heretics. We explore the changes in family law, where divorce became more difficult and the authority of the paterfamilias was further curtailed in favor of a new emphasis on the individual's soul. We also look at the growing legal authority of bishops, who began to operate their own ecclesiastical courts. The Christianization of the empire marked the beginning of the end for the purely classical legal tradition. It infused Roman law with a new moral vocabulary and a new set of priorities. This period represents the final, transformative phase of Roman law, creating the legal world of late antiquity that would be inherited by the Byzantine Empire and the medieval West.