The term ‘green economy’ re-emerged over a decade ago as a buzzword in notably inconclusive discussions across the globe amongst politicians, civil servants, business, non-governmental organisations (NGOs), community interest groups, the media and academics. By offering the possibility of integrating economic priorities with more ecologically sensitive and socially just forms of overall progress, the concept of a green economy outwardly seems to provide some guidance and direction for achieving long-term sustainability across a range of tiers of governance and different types of economy. We argue that the notion of a green economy remains elusive and is deeply disputed, often poorly understood and unevenly applied. Hence, it is in danger of remaining both unworkable and marginalised. This chapter traces the development of the concept, not only in Europe but beyond, in order to provide context for the deliberations in Europe. The chapter also outlines contemporary debates, and identifies emerging themes in order to argue that the idea of a green economy, as currently practiced, requires urgent rethinking and application. This chapter also furnishes background for the remainder of this edited volume, in which European case studies are presented that grapple with definitional issues and the practical challenges of implementation.