This paper examines, in their social context, the origins and history of TG4. It notes that TG4 broadcasts mainly but by no means exclusively in the Irish language, being one of the Republic of Ireland's four national terrestrial television services and one of three operated under the umbrella of the state-owned RTE. The paper focuses on the purposes and functions of TG4 and analyses the cultural assumptions that lie behind it. It considers the development of TG4 as an aspect of Irish language policy generally and assesses the channel's significance for contemporary Ireland.