AbstractThis paper considers the interconnected practices of state formation, diplomacy, national identity and sport through an examination of ‘Irish’ involvement in the British Empire Games of 1930, 1934 and 1938. These events had a contradictory role in bolstering diplomatic relations between those who were committed to the empire but also in expressing the aspirations of those who sought independence from it, or a distinct identity within it. State formation and diplomacy played out in sporting contexts — which we term sportcraft — and this process was especially complex in post-partition Ireland. In the period under examination, a gradual but significant hardening of ideologies and identities occurred in certain sports on the island, notably athletics, mirroring the effects of partition and reflecting British and unionist political actions and sportive interests. Original archival and documentary material is presented from state archives in Dublin, London, Belfast and Ottawa, and from official sports collections in Birmingham, London, Stirling, Melbourne (Australia), Hamilton (Canada) and Lausanne (Switzerland). This demonstrates that by the early 1920s, government officials and sports administrators had already recognised the propaganda functions and utility of sport for state formation purposes and for issues of political control, jurisdiction and territorial boundaries.