Randolph's work examines the origins and growth of the core official infrastructural institution of internal dissemination - the postal system, by horse relay. In particular, the chapter draws attention to ways in which such systems of communication depended on, and could act as catalysts for, the development of forms of obligation in local communities throughout the network. In this respect the Russian system is viewed in the context of analogous horse-relay systems in many parts of the pre-modern world.