ENThe nascent Aistijan movement centred around the idea of establishing a Latvian–Lithuanian state following the Second World War. This article surveys the background of the idea, with particular attention to the public diplomacy of Lithuanian American émigrés, demonstrating its prevalence during the First World War. The activities of interwar Latvian and Lithuanian rapprochement societies are outlined, noting the prominence of the Aestii – the earliest recorded inhabitants of the eastern littoral of the Baltic Sea – in both academic and popular history, in addition to the emergence of the Aistijan movement following the Second World War. Examining the initial successes and rapid decline of the movement, the article also charts developments and material circumstances of language learning practices in connection with the idea of a Latvian–Lithuanian state. Keywords Aistija, émigré propaganda, Lithuanian-Latvian state, public diplomacy, rapprochement societies.