In 1985, at the European Council meeting in Milan, the Heads of State and Government proclaimed 9 May as Europe Day, a commemoration intended to celebrate the European Union as a shared political project, honouring the values of peace, cooperation and unity on which it is founded.
The date recalls the vision, at once idealistic and pragmatic, set out in the Schuman Declaration, through which the then French Minister of Foreign Affairs called for the creation of a “de facto solidarity” among European countries, based on growing cooperation that was primarily economic and later also political and social: the first step towards a united Europe capable of ensuring lasting peace for a continent still haunted by the deep wounds of the Second World War.
From this initiative, in 1951, the European Coal and Steel Community (ECSC) took shape, involving the signatory States in the sharing of strategic resources within a common market so that a new war between France and Germany would become “not merely unthinkable, but materially and economically impossible.” This was followed by the Treaties of Rome in 1957, which established Euratom and the European Economic Community (EEC), fostering the gradual alignment of the nuclear and economic policies of the Member States. In 1993, with the entry into force of the Maastricht Treaty, the European Union was born, thus giving institutional form to a far-sighted ambition that continues to evolve to this day.
A decisive step in the construction of the European legal order is represented by the judgment in Costa v ENEL (Case 6/64) which marked the introduction of a principle destined to have a profound impact on the relationship between national law and European law. The case arose in Italy, when a citizen challenged the nationalisation of the electricity sector, arguing that the domestic law was incompatible with the rules of the European Economic Community (EEC). Under Italian national law, two laws of the same rank are resolved according to the chronological criterion: if they are incompatible with one another, the later law repeals the earlier one. However, can a subsequent national law prevail over a provision of the EEC Treaty? The matter reached the Court of Justice through the mechanism of the preliminary ruling under Article 177 of the EEC Treaty (now Article 267 TFEU) giving the Court the opportunity to clarify the relationship between the European Community and domestic legislation.
With this judgment, the Court held that the Member States had limited their sovereignty, in certain areas expressly defined within the Community system to which they had adhered, by transferring competences to an autonomous, distinct and superior legal order. From this derives the principle of the primacy of Community law: European rules cannot be rendered ineffective by subsequent national provisions, since this would undermine the effectiveness and uniformity of the entire system.
From that moment onwards, a connection between the Community legal order and national legal orders became consolidated: these were no longer separate systems, but interconnected legal levels, in which European rules penetrate domestic legal systems and guide their direction and development. The relationship between domestic law and European Union law is therefore configured as a continuous dialogue, in which the Court of Justice plays a fundamental role in the uniform interpretation of the law, while national courts ensure the effectiveness and application of European rules.
On the occasion of Europe Day, recalling this emblematic judicial case makes it possible to understand how integration is not merely a political and/or economic project, but also a concrete legal reality, capable of directly affecting the rights and obligations of European citizens.