European Court of Justice in the context of "Technical Group of Independents (1999–2001)"

A supranational union is a type of international organization and political union that is empowered to directly exercise some of the powers and functions otherwise reserved to states. A supranational organization involves a greater transfer of or limitation of state sovereignty than other kinds of international organizations.

The European Union (EU) has been described as a paradigmatic case of a supranational organization, as it has deep political, economic and social integration, which includes a common market, joint border control, a supreme court, and regular popular elections.

The primacy of European Union law (sometimes referred to as supremacy or precedence of European law) is a legal principle of rule according to higher law establishing precedence of European Union law over conflicting national laws of EU member states.

The principle was derived from an interpretation of the European Court of Justice, which ruled that European law has priority over any contravening national law, including the constitution of a member state itself. For the European Court of Justice, national courts and public officials must disapply a national norm that they consider not to be compliant with the EU law.

Flaminio Costa v ENEL (1964) Case 6/64 was a landmark decision of the European Court of Justice which established the primacy of European Union law (then Community law) over the laws of its member states.

The Court of Justice of the European Union (CJEU) (French: Cour de justice de l'Union européenne or "CJUE"; Latin: Curia) is the judicial branch of the European Union (EU). Seated in the Kirchberg quarter of Luxembourg City, Luxembourg, this EU institution consists of two separate courts: the Court of Justice and the General Court. From 2005 to 2016, it also contained the Civil Service Tribunal. It has a sui generis court system, meaning 'of its own kind', and is a supranational institution.

The CJEU is the chief judicial authority of the EU and oversees the uniform application and interpretation of European Union law, in co-operation with the national judiciary of the EU member states. CJEU also resolves legal disputes between national governments and EU institutions, and may take action against EU institutions on behalf of individuals, companies, or organisations whose rights have been infringed.

In law, a question of law, also known as a point of law, is a question that must be answered by a judge and can not be answered by a jury. Such a question is distinct from a question of fact, which must be answered by reference to facts and evidence as well as inferences arising from those facts. Answers to questions of law are generally expressed in terms of broad legal principles. They can be applied to many situations rather than particular circumstances or facts. An answer to a question of law as applied to the specific facts of a case is often referred to as a conclusion of law.

In several civil law jurisdictions, the highest courts deem questions of fact as settled by the lower courts and will only consider questions of law. They thus may refer a case back to a lower court to re-apply the law and answer any fact-based evaluations based on their answer on the application of the law. International courts such as the Benelux Court of Justice and the European Court of Justice will only answer questions of law asked by judges of national courts if they are uncertain about the interpretation of the law of multilateral organizations.

The General Court, informally known as the European General Court (abbr. EGC), is a constituent court of the Court of Justice of the European Union. It hears actions taken against the institutions of the European Union by individuals and member states, although certain matters are reserved for the European Court of Justice. Decisions of the General Court can be appealed to the Court of Justice, but only on a point of law. Prior to the coming into force of the Lisbon Treaty on 1 December 2009, it was known as the Court of First Instance.

The Merger Treaty, also known as the Treaty of Brussels, was a European treaty which unified the executive institutions of the European Coal and Steel Community (ECSC), European Atomic Energy Community (Euratom) and the European Economic Community (EEC). The treaty was signed in Brussels on 8 April 1965 and came into force on 1 July 1967. It set out that the Commission of the European Communities should replace the High Authority of the ECSC, the Commission of the EEC and the Commission of Euratom, and that the Council of the European Communities should replace the Special Council of Ministers of the ECSC, the Council of the EEC and the Council of Euratom. Although each Community remained legally independent, they shared common institutions (prior to this treaty, they already shared a Parliamentary Assembly and Court of Justice) and were together known as the European Communities. This treaty is regarded by some as the real beginning of the modern European Union.

This treaty was abrogated by the Amsterdam Treaty signed in 1997: