This article investigates and classifies the different meanings of the term sovereignty. What exactly do we try to convey when using the words “sovereign” or “sovereignty”? I will argue that, when saying that X is sovereign, we can mean five different things: it can mean that X holds the capacity to force everyone into obedience, that X makes the laws, that the legal and political order is created by X, that X holds the competence to alter the basic norms of our legal and political order, or that X is independently active on the international stage. These different usages of the term are of course related, but they are distinct and cannot be fully reduced to one another.

This article challenges the assumption, widespread in European constitutional discourse, that ‘national identity’ and ‘constitutional identity’ can be used interchangeably. First, this essay demonstrates that the conflation of the two terms lacks grounding in a sound theory of legal interpretation. Second, it submits that the requirements of respect for national and constitutional identity, as articulated in the EU Treaty and in the case law of certain constitutional courts, respectively, rest on different normative foundations: fundamental principles of political morality versus a claim to State sovereignty. Third, it is argued that the Treaty-makers had good reasons for writing into the EU Treaty a requirement of respect for the Member States’ national identities rather than the States’ sovereignty, or their constitutional identity.