From the late 18th century to the end of the Habsburg Monarchy in 1918, Vienna’s two Greek Orthodox communities administered a remarkable number of endowments. By founding endowments the benefactors acted between several spaces and subspaces. The transgression of boundaries by endowments addressed to the benefactors’ hometowns in the Ottoman Empire as well as the instability of these boundaries in the 19th century led to various problems in the interaction with the state authorities. But also endowments given to Viennese institutions were sometimes problematic, depending on the benefactors’ character as either Ottoman or Habsburg subjects. In contrast to Ottoman subjects, Habsburg subjects could also endow real estate and thus show their integration into the Viennese bourgeoisie. In this article we discuss the legal frameworks for the administration of endowments in the two Greek communities in Vienna as well as its practical realization in interaction with the Habsburg authorities.