Aspects of legal and sociological problems of the citizenship institution

The topic of the right to citizenship is undoubtedly quite broad and its research is expanding, as more and more theorists are discussing the ways in which many crises influence the concept of citizenship. Citizenship is a principle that is the source of the legal-political link between the state and the citizen, at the same time, the concept evaluates as it evolves and develops states. That article will examine the institution of citizenship as a notion of law. The specific nature of this institution is explained by the fact that it integrates elements specific to several branches of law. The legal notion of citizenship results mainly from constitutional law, because it is the expression of sovereignty, namely this right determines the actual content of this institution. The purpose and objectives of the article are to reflect the institution of the right to citizenship, its guarantees and limits, as elements of constitutional law, subject to expertise the compatibility of national and international constitutional limits in the field of protection of the right to citizenship with the rules of the ECHR Convention and the case law of the EctHR,to argue for changes in order to adjust national to international ones.