Canon Law of the Roman Catholic Church
The Roman Catholic Church has the oldest continuously functioning legal system in the Western World, predating the common and European civil law traditions. What began with rules ("canons") adopted by the Apostles themselves at the Council of Jerusalem in the First Century has blossomed into a highly complex and original legal system encapsulating not just norms of the New Testament, but key elements of the Hebrew (Old Testament), Roman, Visigothic, Saxon, and Celtic legal traditions spanning thousands of years of human experience.