This paper surveys the development of the institution of the fundug in the Islamic Mediterranean world, from its pre-Islamic origins as the Byzantine pandocheion until the fifteenth century AD. This institution mediated relations between different cultural and religious groups in the medieval Islamic world and was itself transferred, in slightly differing forms, between groups. By the twelfth century, the funduq had evolved into the parallel form of the fondaco, the Latinate term for hostelries housing communities of Western Christian merchants in Muslim Mediterranean cities. At the same time, the fundug also served as a charitable facility in the Egyptian Jewish community, as testified by documentation in the Cairo Geniza.