This article compares the content and impact of two iconic lectures concerned with language revival in Ireland and Wales. The lectures are Douglas Hyde's ‘The Necessity for De-Anglicising Ireland’ of 1892 and Saunders Lewis's Tynged yr Iaith (Fate of the Language) of 1962. It explores the different types of ‘public’ addressed by these lecturers and contrasts the languages used to address those publics, as well as assessing the significance of the media of communication for how the two lectures were received. This diachronic comparison raises questions about how public intellectuals have, at different times, sought to defend and enhance the position of non-state languages in the United Kingdom and illuminates the role of cultural nationalism in different parts of that state. In addition, it argues that a diachronic comparison enjoins a clearer evaluation of historical context, a feature of the analysis that can be both problematic and illuminating.