This chapter discusses the Court’s 1970 judgment, Internationale Handelsgesellschaft, where the Court declared that the Court of Justice itself would take on the role of reviewing whether European legal obligations were in conflict with the fundamental rights of individuals. This judgment is often understood as derived from the sensitive relationship between the Court of Justice and national constitutional courts that wished to protect the fundamental rights set out in their national constitutions. This chapter demonstrates, however, that in Germany and Italy the national constitutional courts had already developed an accommodating approach to potential conflicts between treaty obligations and national constitutional law fundamental rights, and therefore that the possibility of clashes between European law and national constitutional law fundamental rights in the early years of European legal integration was less of a practical challenge than is often understood.