According to al-Muqaddas? (writing in the late fourth/tenth century), the city of Baykand was surrounded by one thousand rib??s. The nature of the rib?? as a type of fortification has long been an interest of scholars of the medieval period. A consensus is forming that rib?? should properly refer to an activity (raba?a) associated with the defense of frontiers that takes place at certain locations which are then referred to as rib??s, rather than a particular architectural form. While this definition gives us some direction toward understanding the nature of these frontier fortifications, it leaves questions about the foundation, ownership, and maintenance of rib??s in the medieval period. Who built rib??s (or rededicated existing fortifications as rib??s), how and why did a fortification become associated with the activity of raba?a, and how were these fortifications provisioned and manned? In this paper, one case study will be examined to explore these questions. The image of Baykand (or Paykand, but also referred to as “the City of the Merchants”) presented by al-Muqaddas? is one of a city whose rural hinterland was dotted with fortifications forming a defensive network around the city. This is an image that many medieval geographers likewise attribute to a number of other Transoxanian cities during the third/ninth and fourth/tenth centuries. Such statements in medieval sources are often disregarded as exaggerations, but we should presume the existence, in such cases, of a tradition of fortification construction in a region so described. Why were such networks of fortifications needed and who was responsible for their construction and maintenance? In this paper, the history of fortifications in and around Baykand during the Islamic era will be examined to date the appearance of these rib??s. This history will then be compared to the history of settlement in and around Baykand over this same period, with special emphasis on the resettlement of local merchants during the period of the conquests, to identify the origins of these rib??s. Comparisons will be made to nearby cities, such as Bukh?r?, in order to explore the broader tradition of rib?? construction in the region.