The legislative changes in the field of ecclesiastical and canon law have followed one another with an intensity that in few other areas of legal science could be found, so that they cannot be considered in a predominantly historical dimension, but are a very current and positive expression of the life of law. In the course of a century, two Codes of Canon Law, in addition to the Constitutions and Decrees of the Second Vatican Council, two Concordats, in 1929 and 1984, a new Constitution, that of 1948 and the reform of 2001, and continuous changes in the sphere of common law necessitate a different arrangement of sources and a re-evaluation of the concordat dynamic and the problems of international ecclesiastical law, so that their subject matter can be redefined.