The Concrete poetry movement was an international movement of visual and sound poetry during the nineteen sixties. This thesis is an account of the Concrete poetry movement's history in Britain and its relationship to the concept of avant-gardism. It presents Britain's contribution towards the movement and an account about an aspect of Britain's own literary history which has otherwise remained neglected. This account of the Concrete poetry movement in Britain is presented through the concept of the avant-garde, meaning an arts movement which challenges cultural and social tradition. The primary research question of the thesis is: in what way did the Concrete poetry movement behave as an avant-garde? The thesis argues that the Concrete poetry movement in Britain was a post-modem avant-garde through its existence as a decentred group and through the way that its poetry was formally innovative; a challenge to the realist convention of the author; and on the side of libertarian politics. The first chapter addresses the notion of an avant-garde as a historical movement and introduces the Concrete poetry movement in Britain as reflective of a post-modem kind of radical arts group. The remainder of the chapters address the notion of avant-gardism as a challenge to cultural and social tradition in relation to Concrete poetry and its post-modem context. The second chapter considers Concrete poetry's relationship to the concept of the new; the third chapter considers Concrete poetry's relationship to the concept of the author; and the fourth chapter concludes the thesis by considering Concrete poetry's relationship to libertarian politics.