The Blue Nile Basin has for the past century been characterized by Egyptian dominance, both directly and through British colonial rule. This dominance is institutionalized through the Nile Water Agreements and the Anglo-Italian Agreement of 1902, which grant Egypt and Sudan the right to divide between them the entirety of the Nile, as well as the right to veto any construction on the river. This veto right and the treaties it is based on are currently being contested by the construction of The Grand Ethiopian Renaissance Dam (GERD) across the Blue Nile close to the border with Sudan, which openly has declared support for the project. Given the historical relationship between Sudan and Egypt, this is a move of no small significance. Sudan has historically been a staunch ally of Egypt, who in turn has largely assumed Sudanese support for its Nile policy by default and for the past two centuries has been working towards greater integration between the two countries. The point of departure for this study is the assumption that GERD represents not only a physical subversion of Egyptian dominance on the Blue Nile, but also a subversion of the ideas, narratives and discourses that support this dominance. Looking at the Sudanese support for the construction of GERD as an expression of this subversion and seeing representations of dominance as concrete acts either supporting or contesting that dominance, the aim of this study is to investigate the ideological dimension of the ongoing power shift in the Blue Nile basin through looking at how Egyptian and Sudanese media discourses represent Egyptian dominance. The findings, in short, are that Egyptian discourse legitimizes dominance by representing the basin as characterized by equality and the rule of law, with Egypt inhabiting the position of basin leader due to historical and geographical conditions. Sudanese discourse entails a limited subversion of this, contesting the Nile Water Agreements as the basis of basin regulation and asserting greater rights for the upstream countries to utilize the river. At the same time, it is found that a prescriptive idea of shared interests remains the focus of both ideologies. A secondary aim of this study is to situate its methodology, theory and findings in relation to the established school of critical transboundary water studies known as hydro-hegemony. Through addressing what it is argued is a lacking understanding of the nature and role of ideology in hydro-hegemonic theory, the aim is to provide a better foundation for further theoretical and empirical research on ideology both in the Blue Nile Basin and, it is hoped, in international river basins more generally.