It is very likely that no society has existed without water laws of some sort. The fundamental reason for this unique situation is that water is the only truly universal resource that all societies at all times have had to control, relate to and often share. Since water, at the same time, always runs through the societies it helps to create and sustain in different ways, and these societies, when exploiting such a resource, enter into particular relationship with their water systems, different water law traditions have developed in different localities, regions and river basins. Comparative studies of water law in this perspective are an undeveloped field. In order to understand the great variety in water law systems and their characteristics, it is necessary to analyse the water systems as well as the particular histories of the regions in which these legal traditions developed. It is crucial to understand that for a long time water law developed in a highly local manner that reflected the history, geography and political systems of the areas concerned. It is also important to understand how these contexts of time and specific localities have shaped the legal discourse. At the same time, it is striking how the different water law systems of the world exhibit certain recurring patterns. This is partly the result of the diffusion or migration of ideas about water management and water law, but it also reflects the fact that water is not only particular; it is also always universal, in the sense that water is the same everywhere: constantly in flux, always seeking a lower point, and ultimately escaping efforts to control it. This chapter will reconstruct the historical and geographical context of the Nile Waters Agreement of 1929 as a case in point.1 One of the first places where water law developed was along the River Nile, during the time of the pharaohs. The discussions in this part will not focus on this early period, however, but on the development of Nile agreements in the modern epoch, especially during the colonial period when the British Empire was still the dominant power in the region.