Bath-houses are a frequent part of Roman military installations in Britain. This work explores differences in the social meaning of bathing between legionary fortresses and auxiliary forts. It demonstrates variations in the scale of and investment in these facilities between the two groups. It also argues for greater complexity in the legionary bath-houses, with duplication of facilities, and more activities being catered for. A comparison of the proportion of space allocated for bathing and non-bathing activities reveals that the two groups respond to different ideas of what a visit to the bath-house entailed.