Humanist History and Architecture in Sistine Rome is a book-length manuscript that investigates fifteenth-century humanist historical theory and its relationship to architectural design by focusing on the monumental hospital of S. Spirito in Sassia, built near the Vatican in the 1470s. Modern scholars have viewed its architecture as the product of an uneducated architect. This study argues that is a misperception generated by current expectations concerning Renaissance architecture and shows the hospital was produced by a group of vanguard artists and intellectuals from the Veneto. The hospital is characterized by an architectural proportional system that enabled the harmonious incorporation of both medieval and ancient architectural elements. That architectural as well as conceptual framework embodied a new philological understanding of history and exemplified a northern Italian approach to the search for a new architectural language, offering an alternative to the Tuscan suggestions of the earlier part of the century.