This chapter introduces the theoretical frameworks and constructs of archival memory, the premise that underpins the following chapters and studies within the book. Detail is given to the context to the period in question, from the onset of the 1950s through to the end of the 1970s, which is characterised as being years of modernisation, in terms of political and social change. This is mirrored with a study of the characteristics of the modernisation of Irish drama, theatre and performance within the same period. These facets form the basis through which archival memory is applied to the study and understanding of the marginalised histories of modern Irish drama. Methodologies of memory study are positioned within a performance studies framework, where the ‘present absence’ of the archive affords an opportunity to reassess and challenge canon formation and present historiography of modern Irish drama and of the modern Irish State.