On November 1, 2023, it was three decades since the entry into force of the Maastricht Treaty that established the European Union. The project of founding this organisation was widely debated in previous decades. After the Paris Summit of 1974, the prospect of such an organisation seemed closer to completion but still too timidly assumed by the European leaders to materialise. An important step was achieved in 1979 when the first direct vote for the European Parliament took place. That can be considered the first concrete gesture in the sense of the democratisation of European construction. Beyond the entire institutional architecture and the clarification of the community decision-making mechanism, the Treaty of Maastricht introduced the citizenship of the European Union.