Abdullah Quilliam and Marmaduke Pickthall are arguably the most significant British converts to Islam in the period of their lifetimes. Much has been made of both men’s attempts to balance loyalty to Islam with their membership of the British nation. This chapter discusses the context of their leave-taking from Christianity before situating them as international Muslim actors. It probes their divergences, notably over the issue of Sultan Abd al-Hamid II’s Caliphate and pro-Turkish agitation during the First World War, and their similarities on the Ottoman issue and its relation to their visions of Islam as a living faith