Today, the European environmental regime seems omnipresent. A rare beetle can stop a building project, the local water authorities have to make sure that the European Eel can reach his home waters after having travelled the Atlantic, European standards for air quality cause trouble for the German diesel-driven car industry, and lighting products are subject to EU energy labelling and eco-design requirements. Implementing laws and sticking to environmental norms and standards has become an integral part of the European integration process. To the EU this is self-evident: We share resources like water, air, natural habitats and the species they support, and we also share environmental standards to protect them. The idea of any such 'shared environment', however, has come a long way and is still being contested. Thinking and writing about the history of protecting the environment requires us to study the long 20th century. In order to understand the peculiar rise of Europe environmental regimes and green values we have to consider the modern concept of Europe as a shared geographical space, linked by habitats, migrating species, rivers, pollutants, climate and risks. Moreover, we have to analyse the 'invention' of conservation as a moral enterprise. That is why environmental history needs a long durée's perspective to understand the evolution of the European Common.