This paper argues that concubinage was a major locus around which Christian religious elites in the early Abbasid Caliphate articulated new conceptions of non-Muslim community and personhood. Juxtaposing discourses on concubinage in Syriac Christian legal works with accounts of concubines and Christian men in biographical dictionaries, the paper argues that lay Christian administrators and physicians practiced concubinage – condemned unequivocally by Christian tradition – to embody their belonging to the elite, male echelons of the Abbasid court. Christian bishops responded not only by prohibiting concubinage as unacceptable polygamous sexuality, but by creating a Christian law of inheritance sharply opposed to that of Islam. Unlike Islamic law, Syriac Christian inheritance law did not allow the sons of unfree women to inherit from their free fathers, and at times it went so far as to claim that those sons should remain slaves themselves. In other words, Christian law closed off concubinage as a strategy for social reproduction: whereas many elite Muslim men received family status from their fathers while at the same time being sons of concubines, Christian inheritance law tried to preclude the potential for Christian men to pass on status to the progeny of extra-marital, servile unions. Even if Christian men might not always obey the ecclesiastics’ prohibition of extra-marital sexuality, this inheritance law would sculpt Christian communities in Abbasid society according to the monogamous, ecclesiastical ideal. In this manner, concubinage was not only a social practice contested between lay and ecclesiastical elites because of its Islamic associations, but one that allowed Christian religious elites to articulate a vision of the specific shape their non-Muslim communities should take within the Islamic Caliphate. Equally as important is the conception of unfree, gendered personhood this Christian discourse constructed. Doing away with the umm walad and her free children as a legal category, this discourse retrenched conceptually the division between the free and the unfree that was such a constitutive feature of medieval eastern Mediterranean societies.