How is it possible that originally mainly economic organization becomes after 50 years the subject which attempts to achieve its own legally binding catalogue of fundamental laws? And most importantly - which actors stay behind this shift? The attempt to understand integration and to explain why states cooperate and give up their decision monopoly in behalf of supranational subject is provided with classical integration theories of intergovernmentalism and neofunctionalism, which are nevertheless considered to be obsolete by now. That's why the author also addresses contemporary theories of European integration which are supposed to give better explanation of the integration process. The book is not primarily aimed towards application of the theories - instead, it tries to propose its own generalizing schema to explain continuing widening of European Union's competencies. In particular, it attempts to come up with explanation of the entire process of incorporating human rights agenda into European Union's sphere of action.