The paper discusses the problem of the religious freedom according to the Edict of Milan (313). The Author starts with the explanation of the notion of the religious freedom as a fundamental value that comes from the dignity of the human person. This freedom is the law rooted in the nature of the human person. The article provides a thorough analysis of the Edict of Milan in the context of the religious freedom. The celebration of the 1700th anniversary of the Edict of Milan is the basic reason of the presented article. The Author describes the reasons of the promulgation of the document and its content This is due to the fact of the religious and political dualism based on the words of Jesus Christ who declared: “render therefore unto Caesar the things which are Caesar’s, and unto God the things that are God’s” (Matthew 22:21; Luke 20:25). In the article it is emphasised that the Emperor Constantine I exposed the importance and value of the Christianity for the development and security of the Roman Empire. The Edict granted liberty to Christianity and other religions.