AbstractThe martyrdom of Yūḥannā, physician of Ibn Abī ’l-Ḥusayn ruler of the island of Sicily, is a text which is edited, analyzed and commented on here for the first time. Yūḥannā, after having refused to convert to Islam, is implicated in a trial for having blasphemed against the prophet Muḥammad, which is a crime punishable by death. At the end of his trial, Yūḥannā offers himself up as a voluntary martyr. Aside from the story itself, the aim of the present study is to establish the context in which the story was produced and disseminated. Yūḥannā’s account is an explicit call to resist the Islamization of the Melkite community (i. e. apostasy from Christianity and conversion to Islam), and to find examples of resistance beyond Fāṭimid Egypt or Syria-Palestine, in a land situated at the outer limits of the empire: Kalbid Sicily.