This book presents the first part of an investigation in the possibility of a universal territorial architecture with a radically simple materiality. Essentially, our contemporary iteration of the Roman project is a negotiation of the European territory through the architectural project. Europe here has to be understood as a cultural and geographic entity with an enormous cultural diversity but a fascinating cohesion. The Roman project is an attempt to understand this territory as an Even Covered Field. If Europe has originally been the cradle in which the figure-ground relationship developed, it becomes now of utmost importance to look again into the place of its obsolescence. Our studio’s core interest is to better ‘define’ the even covered field and to look for tools to design in it. Manoeuvres that are capable to create hierarchies and points of reference are crucial to aspire for a certain order in a world increasingly hard to grasp. For all this, Roman Architecture is our guide, as we believe it is precisely in this proto-architecture that we find the kernel of an enlarged understanding of the architecture of hierarchies. It is about time to revive this radical and simple idea of a proto-architecture, as it might give a valuable answer to our current and fundamental desire to build without waste, to embrace a veritable equilibrium between living, working and the world. It is now that we can develop fundamentals of sustainability, not through silly rhetoric, but through the re-development of an ancient relationship between man and territory, since any architecture should celebrate the act of building as a substantial effort produced by any society in a necessary long-term perspective. Roman Architecture has the disproportionate ambition to create a base for this endeavour. It is presented here as a treatise, owing a lot to the impressive tradition developed in western architecture in the past six centuries, after the Renaissance started reworking the seminal work by Vitruvio. Its most direct ancestor is the Entwurf für eine Historische Architektur by Fisher von Erlach, although also the Recueil et parallèle des édifices de tout genre, anciens et modernes … by Jean-Nicolas-Louis Durand plays a fundamental role in the final definition of its content. In the course of the research, three meta-chapters have been defined, like magnetic cores able to coagulate certain constellations of projects, to organize them meaningfully. The overall collection comprises—as an echo of the organization of the Entwurf—sixty ancestors, spanning from the Pyramids of Cheops to Patchinko Parlor III, plus fifteen new projects that bridge between these. Together they present a possible canon of a universal territorial architecture with a radically simple materiality.