The nation-state is a concept in which different federating units agree to surrender some part of their sovereignty in favor of federation and in return all the federating units get common security from external threats and federation follows a common foreign policy. This is not the all-exclusive list of rights and duties of a state though. In a nation-state, the constitution is the fundamental document which governs these rights and liabilities of federating units, its basic structure of governance, its legal system, a form of government, a system of local governance, rights of its citizens and another basic treatise which are required for the smooth functioning of any form of government. This constitution is always in line with the wishes of the people of these federating units in a manner agreed by all. That is the reason that it is considered the supreme law of the land.In the light of the above a question strikes the mind. that what makes a constitution supreme? It is the will of the people who show their allegiance to it and agree to abide by it, through the mechanism of the state. This constitution might or might not be in the form of a single document. It may also be an unwritten constitution as in the case of the UK, a brief and short document like the constitution of the USA or a lengthy document as in the case of France.European Union, unlike a true federation, is a quasi-federating set up created among the sovereign states of Europe to bring homogeneity and commonality among these nation-states. In order to achieve this objective, the member states have passed through a number of historical phases starting from the concept of the European commission to a single market and free market to the European parliament. This process started soon after the end of the Second World War and lasted a span of over six decades. But it would be wrong to conclude that Europe has reached the pinnacle of mutual harmony and understanding and is now capable to be governed under one supreme legal document.