This article analyses Francesco Giammaria’s Capitolium Novum, a Latin poem describing a tour of the historic center of Rome in 1933, in its historical, architectural, and intellectual contexts. It offers a detailed analysis of three key sections of the poem, which deal with the Colosseum, the Arch of Constantine, and the Ara dei caduti fascisti respectively. The authors show how Giammaria’s poem responds to urbanistic interventions in the city center during the ventennio, and specifically to the Fascist ‘recoding’ of the city as the ‘Third Rome’, with a narrative emphasizing the historically layered nature of Rome. Giammaria offers his own interpretation of the respective importance and interrelation of the city’s historic layers: the rhetoric of his poem is aimed at superimposing Catholic Rome over pagan Rome, and at framing all historical layers of the city, including the Fascist one, as part of its Christian mission and destiny. Thus, Capitolium novum resonates with efforts of intellectuals gathered around Carlo Galassi Paluzzi’s Istituto di Studi Romani, who aimed to promote a cultural reconciliation between Fascism and Catholicism.