Environmental law and policy has come a long way since the birth of the US Environmental Protection Agency in 1970 and the launch of the first European environmental policy in 1972. Today law is no longer centre stage but simply one instrument among others in the environmental regulator's toolkit. And talk of regulation may itself be giving way to the broader concept of environmental governance. This article examines the evolution of environmental law, regulation and governance over almost four decades. It explores the major initiatives of that period and the lessons that can be learned from them, it maps shifting regulatory architectures and explains what has worked and why and it considers the changing nature of the environmental challenge itself. Finally, it seeks to identify which particular architectures are most suited to deal with particular types of environmental problems.