This paper seeks to explore the regulation of the religious "other" in Byzantine Law during the Long Late Antiquity by examining how heretics, Jews, pagans and Muslims were regulated. While analyzing the legal treatment of these first three groups is relatively well-researched and for the most part a straightforward proposition, examining the actual implementation of imperial legislation is more difficult. The regulation of the last of these four groups, Muslims, is even more problematic, because Byzantine law, due to the overriding importance of the Justinianic codification of Late Roman law, was emmeshed in a sixth-century context before the rise of Islam. The terminology used for Muslims in Byzantine legal texts as well as Byzantine literature more broadly was marked by profound variation, so that they were variously classified as Jews, heretics or pagans, but only rarely as an independent group. In this talk both legal texts (civil and canon law) as well as mentions of the legal treatment of non-Orthodox Christians in other sources (hagiography, historiography, etc.) before ca. 1100 will be analyzed to see how Byzantine jurists and secular authorities evaluated and moved between categorizations of the religious other.