This paper combines documentary evidence with concepts and tools of historical network science and social theory in order to explore phenomena of (especially) mercantile mobility and religious conversion in the late medieval Byzantine world. The intensification of commercial exchange and the multiplication of contact zones between ethnic and religious identities in the 13th to 15th centuries, both due to the growth of the activity of Italian merchant communities as well as due to the Mongol expansion across entire Asia, facilitated the change of places of residence and/or of religious confession for elite as well as non-elite members of these societies. With the help of network analytical and sociological concepts, potential underlying mech...