The invention of a new form of hot-air bath in Blarney, Ireland in 1856, variously known in its lifetime as the Roman e Irish or Turkish Bath , acted as the starting point for a the production of a globalised thera- peutic landscape. Tracking the diffusion of the Roman e Irish bath template from its local invention in Ireland to a global reach across the Victorian world and recognizing its place within a wider hydro- therapeutic history, this paper frames that diffusion as a valuable empirical addition to assemblage theory. The speci fi c empirical history of the spread of the Roman e Irish/Turkish bath idea is drawn from primary archival and secondary historical sources. It is then discussed and, drawing from work on assemblage theory, analyzed against three broad themes: mobile networks, socio-material practices and contested emergence. The emergent relational geographies of the Roman e Irish Bath identify important roles for the diffusion and transformation of speci fi c medical settings, identities and functions. These were linked in turn to competing social-healing pathways wherein bodies were technologically and morally managed, to produce a more inhabited form of therapeutic assemblage. In all cases the differ- ential diffusion of the bath idea, it ’ s shifting and fractured material forms and multiple inhabitations and discourses were contested and mobile and spoke to an assemblage approach which has ripe potential for exploration across a range of medical/health geography settings.