After the longest crisis in Belgium’s political history, the sixth reform of the state (2012-2014) required the revision of no less than forty-seven constitutional provisions and the adoption of a large number of special laws, ordinary laws and cooperation agreements between the federal state, its communities and its regions. This book aims to take stock of the changes that this reform is bringing to the constitutional law of a state which is hit hard by independent demands, but at the same time faces the Europeanisation of its legal system, the internationalisation of fundamental rights and the universalisation of economic, ecological and security concerns. Viewed from the perspective of positive law and legal theory, this book is characterised in particular by an original conception of the foundations of constitutional law, by the formulation of a general theory of rights and freedoms in Belgian law, by the inclusion of international and European rights data in the constitutional framework and by the review of the relationship between the Constitution and European Union law. It takes account of the latest developments in current legislation and case-law, which is the first in Belgian constitutional law in French, incorporating all the amendments resulting from the new reform of the State. It is designed to meet the needs of students and practitioners of constitutional law, but also of all those who are interested in public law and, more fundamentally, on the legal basis of the state and its power.