The tercentenary commemorations in 1967 of Borromini’s death had demonstrated how an historical subject like the oeuvre of this key figure of the Roman baroque could sustain the attentions of many varied modes of historical analysis. Lectures, exhibits, books, films and many other interventions treated Borromini’s buildings (realized and otherwise), his drawings and inventories (as sources and documents alike), the Opus Architectonicum, secondary historical and biographical accounts and so forth as legitimate historical subjects. They had visited upon them the disciplinary tools of art historians from Rudolf Wittkower to Giulio Carlo Argan alongside new scholarship by those invested in Borromini’s archives, in the restoration of his buildings, in his manner of design, in his reception and in the lessons offered by his work to the present. Borromini emerged from this event as a complex and interdisciplinary historical and biographical subject that could exist in an architectural culture experiencing a watershed moment of disciplinary maturity – a form of détente between conflicting historiographical investments, with the academic and public program of the anno borrominiano demonstrating a format within which these interests could occupy the same corpus. The investment of the architect-historian in such a figure as Borromini was, at this time, as legitimate as that of the art historian specializing in architecture (or, even generally, in the art of the seventeenth century), as was that of the architect practicing (and thinking) in a manner demonstrating his or her cognizance of the present’s historicity.