Ritual brotherhood, or pobratimstvo, is attested by a range of sources dealing with the Adriatic hinterland between the sixteenth and eighteenth centuries. Read one way, pobratimstvo shows us a border society characterized by cohesion and tolerance, where Christian and Muslim frontiersmen find ways to overcome religious and political boundaries, recognizing their common interests and shared values. Read another way, however, the same institution (and sometimes even the same documents) also offers an insight into the persistence of frontier conflict and the pervasiveness of its violence, drawing attention to other, no less bloody divisions between predators and victims. In teasing out some of the possible meanings and uses of ritual sworn brotherhood on this early modern frontier, I attempt to give due weight to the complexities of a specific place and culture. But the problems highlighted by the institution of pobratimstvo are more widespread: the troubling ambiguities of friendship, with its quality of simultaneously including and excluding; the boundaries between affection and interest, or between camaraderie and desire; the obligations (and the potential resentment) conferred by gifts; the moral dilemmas posed by cross-cutting obligations.