If Western classical architecture has a founding document—a Declaration of Independence or a Constitution establishing the ground rules of the discipline for generations to come—it is undoubtedly the Ten Books on Architecture by the first-century Roman architect and military engineer, Marcus Vitruvius Pollio. His text offers a comprehensive overview of architectural practice and the education required to pursue it successfully. Like any foundational document that has endured, it is imperfect, but, also like any good constitution, it not only offers practical guidance but also defines the means to adapt its precepts to changing conditions. Paraphrasing Alfred North Whitehead’s famous declaration that Western philosophy is largely a set of footnotes to Plato, our architecture since the Renaissance may be viewed as a series of commentaries on Vitruvius. While it is not the only book on architecture to have been written in ancient times (Vitruvius alludes to several even older texts in the course of his presentation), the Ten Books is the only such text to have survived into the modern era. We know little about its reception in the Roman world, and there is reason to think it may have had little impact, since contemporary and subsequent Roman architecture moved in rather different directions. But upon its rediscovery, translation and publication in the fifteenth century at the start of the Italian Renaissance, the work of the Augustan architect would set the terms of architectural discourse for the next six centuries.