In Roman society, adulterium and stuprum referred respectively to illicit sexual relations with a married woman and with a virgin or a widow. In the Augustan age, these illicit behaviours - until then prosecuted within the family sphere - became public crimes and were therefore subject to legal prosecution. Such conduct was regarded as socially dangerous because a woman who engaged in it was thought to contaminate the purity of the family bloodline, of which she was considered both bearer and guardian, and to fail in her primary role of producing legitimate offspring. For this reason, female marital infidelity, which - if openly manifested - obliged the husband to divorce, continued to be regarded as a valid ground for repudium even in Late Antique legislation. By contrast, the idea of infidelity as an offense against marriage itself, regardless of which spouse committed it, an understanding promoted above all by Christian ethics, was not fully incorporated into Roman legal thinking.