A number of relatively undeformed late middle Proterozoic volcano-sedimentary basins are aligned along the western and northern margins of the Kalahari Craton. Although the assemblages of these basins have been compared and lithologically correlated by many authors, radiometric ages partly contradict these interpretations. Attempts to incorporate all of these basins into a regional structural interpretation have been rare. Watters' magmatic arc interpretation is contradicted by the overall geochemistry of the volcanic rocks, the coarse continental red-bed sediments and the structural style of the basins. The depositional troughs were narrow, fault-bounded continental rift grabens with a structural style and sedimentation pattern controlled by strong vertical tectonism. The development of the basins along two branches of a propagating continental rift system, the Koras-Sinclair-Ghanzi Rift (KSG-Rift), is proposed. Radiometric ages reveal a distinct younging along the rift from the southern toward the northeastern branch. The geophysical signature of the rift is dominated by positive Bouguer gravity anomalies, flanked by gravity lows which follow a linear trend. The basins contain distinctly bimodal volcanic rocks with some intermediate volcanics in the Sinclair basin. Contemporaneous with the extrusion of the volcanics, granitic high-level intrusions were emplaced along the rift. The possible existence of a northern, coastal branch of the KSG-Rift and the location of a triple junction is discussed. The rift process possibly continued and led to the development of the early Damara rift in SWA/Namibia. The African plate (Kalahari and Congo Cratons) migrated southward between 1050 and 950 Ma ago. A stationary mantle plume probably caused the development of both the KSG and Damara Rift. A comparison with rift migration in Kenya is drawn. The regional trends and structures of the KSG-Rift were reactivated several times, undergoing both extension and compression. The most prominent of these events was the development of the Damara Orogen, which followed the regional trend of the late middle Proterozoic rift, but fault structures have been reactivated up to recent times.