Given the long history of map-making and its scientific and scholarly traditions one might expect the study of cartography and mapping theory to be relatively moribund pursuits with long established and static ways of thinking about and creating maps. This, however, could not be further from the truth. As historians of cartography have amply demonstrated, cartographic theory and praxis has varied enormously across time and space, and especially in recent years. As conceptions and philosophies of space and scientific endeavour have shifted so has how people come to know and map the world. Philosophical thought concerning the nature of maps is of importance because it dictates how we think about, produce and use maps; it shapes our assumptions about how we can know and measure the world, how maps work, their techniques, aesthetics, ethics, ideology, what they tell us about the world, the work they do in the world, and our capacity as humans to engage in mapping. Mapping is epistemological but also deeply ontological – it is both a way of thinking about the world, offering a framework for knowledge, and a set of assertions about the world itself. This philosophical distinction between the nature of the knowledge claims that mapping is able to make, and the status of the practice and artefact itself, is intellectually fundamental to any thinking about mapping. In this opening chapter we explore the philosophical terrain of contemporary cartography, setting out some of the reasons as to why there are a diverse constellation of map theories vying for attention and charting some significant ways in which maps have been recently theorized. It is certainly the case that maps are enjoying something of a renaissance in terms of their popularity, particularly given the various new means of production and distribution. New mapping technologies have gained the attention of industry, government and to some extent the general public keen to capitalize on the growing power, richness and flexibility of maps as organizational tools, modes of analysis and, above all, compelling visual images with rhetorical power. It is also the case that maps have become the centre of attention for a diverse range of scholars from across the humanities and social sciences interested in maps in-and-of-themselves and how maps can ontologically and epistemologically inform other visual and representational modes of knowing and praxis. From a scientific perspective, a growing number of researchers in computer science and engineering are considering aspects of automation of design, algorithmic efficiency, visualization technology and human interaction in map production and consumption. These initiatives have ensured that mapping theory over the past twenty years has enjoyed a productive period of philosophical and practical development and reflection. Rather than be exhaustive, our aim is to demonstrate the vitality of present thinking and practice, drawing widely from the literature and signposting relevant contributions among the essays that follow. We start the chapter by first considering the dimensions across which philosophical differences are constituted. We then detail how maps have been theorized from within a representational approach, followed by an examination of the ontological and epistemological challenges of postrepresentational conceptions of mapping.