To believe that everything can be rendered readable is perhaps a characteristic of the current phase of the knowledge industry, marked by confidence in the electronic mediation of information, within societies of surveillance and under the geo-logistics of the imperial gaze. This paper is concerned with the limits of readability in the history of colonial relations, through a consideration of specific conditions of unreadability of native culture in post-Conquest Peru. At the same time, it seeks to analyse, in certain specific cases, how legibility is produced: which particular cultural practices are necessary to produce it. Thus part of my concern is to press beyond a merely phenomenological account of reading towards one that is both more historical and more aware of the contribution of the variety of textual practices that intervene. In suggesting that to think the unreadable as opaque is characteristic of the limits of a phenomenological approach, my hope, in part at least, is that some light – or darkness – may be shed upon the alliance between current conceptions of knowledge and confidence in universal illumination by surveillance, whether by satellite, camera or other eye of power.