The aim of this study was to analyze the different ways in which the development of constitutional law and principles in Europe today is departing from the traditional model of the nation state constitution. According to that traditional and relatively simple model, constitutional authority resides in the collective people of each nation state, is expressed through the representative institutions of government of each state, and is legally reviewed and validated through the top courts of each state. With the development of the European Union, of sub-state forms of nationalism, of transnational forms of oversight of rights and democracy (e.g. Council of Europe) and democracy and global forms of directive legal control (e.g. United Nations), this situation is changing rapidly. The state constitutional order is becoming less comprehensive and more widely challenged. The study seeks to investigate how, independently and cumulatively, these changes are transforming both the legitimacy and the efficacy of our overall constitutional arrangements today.