The European Union is meant to create ‘an ever closer union among the peoples of Europe’. But who are the peoples of Europe? The overall objective of the project EPoCH has been to answer this question by reading the archives of the drafting of the Treaty of Rome, the first EU treaty. In 1957 when the Treaty of Rome was signed, four out of six of the founding Member States were colonial powers. EPoCH has uncovered how the colonial legal politics of the time shaped the drafting of EU law and, specifically, how ‘peoples of Europe’, chosen as the subject of European integration, designates not citizens of the future Member States and not those who are subjected to its laws and institutions but, rather, those who belong to an ethnic and racial meaning of European nation. Understanding who was meant by ‘peoples of Europe’ is an important finding for society as it helps us reflect on who has been excluded from European integration, and going forward, on how to construct an ever closer union, which benefits all people who live in Europe.