A united Europe – free from wars, longing for political stability and economic prosperity – in the year 1950 was merely an idea that has come a long way from creation and adaptation from the original idea to the Europe as we know it today – a single area for freedom of movement of people, goods, capital and services. Initially, the idea of such a Europe was primarily economically oriented, but the subsequent development of this concept of integration was complemented by security aspects that were necessary to create a single area of freedom, security and justice. Although Member States have consistently emphasized their national interests, which they have sought to protect, these interests have always been ultimately overcome by an understanding of the need for integration in order to achieve a "greater" goal. This concept of progress, based on joint cooperation and strengthening the collective potential of all Member States, involved many compromises and required many adjustments and renunciations of self-sovereignty and the transfer of certain national powers to the Community, later the Union. This paper will present the origins of this unique concept of integration, as well as all common policies, actions and forms of cooperation, both between Member States and the supranational Union with them, which seeks to ensure an internal area of freedom, security and justice, and protect common values.