This article looks at military history through a social lens, focusing on the identity and experiences of the Irish Catholics recruited for service in the British army during the American Revolution, a conflict which occurred before Catholics were legally permitted to serve, but during which significant numbers were recruited nonetheless. Using Irish Catholic recruitment and subsequent service in the 46th Regiment of Foot as a case study, this article will discuss the integration of this group into a regular regiment on the British establishment, arguing that despite contemporary anxieties to the contrary, the incorporation of Irish Catholics into the British army happened smoothly and without negative impact on regimental cohesion and discipline. They became well-integrated, and while their loyalty to the British state can never be definitively proven, they certainly became effective participants in its army and empire. This provides a compelling viewpoint from which to discuss the integration of ‘others’ into Britishness and the imperial apparatus during this period.