Constitutional foundations of modern state in the regional privileges of the Grand Dutchy of Lithuania

The results of the analysis of the regional privileges of the Grand Dutchy of Lithuania, carried out within the scope the research on the history of Lithuanian constitutionality, are presented in the article. It is aimed to determine those provisions, which are the basis of construction and functioning of the modern state power – the nation’s sovereignty, separation of powers, rule of law, parliamentarianism, etc