Kinship networks and social hierarchies provide an important key to the Byzantine Empire's tenacious survival over the course of more than a millennium. This study concentrates on one such social networking strategy, that of ritual brotherhood. No investigation of ritual brotherhood can overlook the Byzantine evidence, for Byzantium is unique among medieval societies in having formally incorporated into its ecclesiastical ritual the ceremony by which the priest's prayers and blessing make ‘brothers’ of two men. Further, the history of the empire provides ample evidence for the concrete implementation of this bond. Hagiographical and historical narratives as well as regulations of secular and ecclesiastical authorities attest to the importance of ritual brotherhood as it was practiced by holy men and patriarchs, aristocrats and emperors. The Byzantine evidence is, unsurprisingly, at the core of John Boswell's argument in his Same-Sex Unions in Pre-Modern Europe,' Boswell drew attention to this interesting and multi-faceted relationship, but he did not explore the full range of sources for ritual brotherhood, nor did he attempt to show how this relationship related to others within Byzantine society.