The European eel (Anguilla anguilla) is the only truly pan-European fish. Distributed across Europe, from Iceland to Sicily, the species consists of a single breeding stock. Today, this species of geographically and genetically unparalleled Europeanness - labelled Eurofisch - faces a Europe-wide crisis. Its numbers have fallen by up to 95% over the past half-century. Studying this cosmopolitan yet critically endangered creature - as well as the Europeans who have caught/eaten/traded/researched it, worried about its decline, and tried to improve its future prospects - opens up fresh dimensions of environmental protection in European history. A fish widely perceived as snakelike and devoid of the Atlantic salmon’s charisma unexpectedly serves as a valuable tool for illuminating what Europe means and what it means to be European, geographically, environmentally, politically, and culturally. These meanings are explored in sections on Europe’s eel heritage, Europe’s eel problem, European eel solutions, and the eel’s European future.