For over a thousand years the Christian churches, Latin and Greek, maintained an ancient prohibition on armsbearing by the clergy, no matter how much individual clerics failed to observe it. The Eastern Church appears never to have relaxed that standard. In the West, on the other hand, in the kingdom of the Franks during the Carolingian period there developed a tacit narrowing in the interpretation of the word ‘clericus’ to exclude bishops and abbots from the ban so as to allow them to discharge their military obligations to the king with something like a clear conscience. Such artful legislation was in any event not promulgated by an independent church, was not imitated elsewhere in Europe, and perhaps inspired a sharp reaction in the ninth and tenth centuries.

Hostility to clerical armsbearing also in part animated the great reform movement which climaxed under papal leadership from the mid-eleventh century onward. One of the objectives of the reform movement was the restoration of the ancient canons. On the issue of clerical armsbearing the reformers renewed and reiterated the prohibition in the most vigorous, unambiguous terms in the whole history of Christianity. No fewer than twelve times in thirty years (1049–79), councils and synods declared flatly that clergy were not to bear arms. Furthermore, popes or their legates presided over eight of those twelve councils.