The plural Islams and the various Christianities deriving from late Antique Catholicism constitute two families of monotheisms whose relation to armed violence and to peace can be compared over the longue durée. In both, war and peace coexist as values, with the sense however that there can be a corrupting bad peace and a wicked bad war. Both—albeit through different media—produced norms governing warfare. For both, there is a strong correlation between holy war and societal reform. In both, the potential to sacralize a space that then has to be defended (New Jerusalems or second Hejaz) figures prominently. In both, radical warfare, reform, and purge of one’s own group can be triggered by apocalyptic or eschatological expectations (with figures such as a person anticipating typologically the return of the vengeful Christ, a last world emperor, a mujaddid, or a Mahdī). While this contribution focuses mainly on the pre-modern world, it ends on an attempt to relate the current war waged by Boko Haram to this past.
