The various names given to the new theatre movement that emerged in the 1960s to challenge both the West End and the new subsidised theatre sector include ‘fringe’, ‘alternative’, and ‘underground’; each offers different aesthetic, social, political, and other definitions of what this theatre movement means. This chapter traces the modern precursors of the movement and the cultural forces that fed into its concerns, forms, and methods, before examining three companies as case studies: Portable Theatre, the Pip Simmons Group, and Monstrous Regiment. Through close analysis of each company’s history, the chapter explore some key features of the fringe that would contribute to its strength but also its vulnerability: its relationship to the mainstream, its collective ethic, and its experience of arts subsidy. Focusing on the period from the mid-sixties to the mid-eighties (perhaps the first wave of the fringe), the chapter asks how far the movement succeeded, whether its radicalism was absorbed by the mainstream or quashed, what contributed to its arguable decline, and what is left today of its legacy of political engagement, artistic experimentation, and much more.