In four experiments, we assessed when the salience of ingroup historical victimization will encourage a sense of moral obligation to reduce the suffering of others. Historically victimized groups (Jews and women; Experiments 1 and 3) who considered the lessons of the past for their ingroup felt heightened moral obligation to help other non-adversary victimized groups. However, when the suffering outgroup was an adversary, Jews (Experiment 2) and women (Experiment 4) who focused on the lesson of historical victimization for their ingroup reported lower moral obligation to reduce others' suffering. The lesson focus effect on moral obligation was mediated by benefit finding as well as perceived similarity to the outgroup. Means to facilitate moral obligation, as well as limiting factors, among victimized group members are discussed. Copyright © 2014 John Wiley & Sons, Ltd.