When British attention was drawn to the issue of leprosy in the Empire, humanitarian organisations rose to take on responsibility for the 'fight against leprosy'. In an effort to fundraise for a distant cause at a time when hundreds of charities competed for the financial support of British citizens, fundraisers developed propaganda to set leprosy apart from all other humanitarian causes. They drew on leprosy's relationship with Christianity, its debilitating symptoms, and the supposed vulnerability of leprosy sufferers in order to mobilise Britain's sense of humanitarian, Christian, and patriotic duty. This article traces the emergence of leprosy as a popular imperial humanitarian cause in modern Britain and analyses the narratives of religion, suffering, and disease that they created and employed in order to fuel their growth and sell leprosy as a British humanitarian cause.From the late nineteenth century, medicine became one of the most prominent humanitarian causes in the British Empire. 1 This medicine was provided primarily by missionaries, and although medical mission was first and foremost an evangelical endeavour, many missionaries also believed that healing the body was a humanitarian responsibility as important as the evangelical imperative to heal the soul. 2 As colonialism expanded, British missions devoted increasingly large proportions of their resources to the promotion of health in the mission field, which primarily lay in the Empire. 3