An essay is presented on the father of Canon Law Gratian and the book "Concordia discordantium canonum" or "Decretum Gratiani" written by him. Topics discussed include the two Piacenza, Italy canons presented by Gratian, his school at the monastery of Saints Felix in Bologna, Italy and Nabor and his devotion towards the study of canon law. It mentions the third part of "Decretum Gratiani" entitled "De consecratione."