Santa Maria del Popolo
The architect or architects of this innovative project remain unknown due to a lack of contemporary sources. Giorgio Vasari in his "Lives" attributed all the important papal projects in Rome during Sixtus IV to a Florentine, Baccio Pontelli including the basilica and monastery of Santa Maria del Popolo. Modern researchers deemed this claim highly dubious and proposed other names among them Andrea Bregno, a Lombard sculptor and architect whose workshop certainly received important commissions in the basilica. The fundamental differences between the façade and the interior suggest that maybe more than one architect was working on the building.
Palazzo dei Convertendi
In 1937, during the construction of the Via della Conciliazione, the palace was demolished, and then reconstructed until 1941 west of Palazzo Torlonia. The relocation was supervised by Giuseppe Momo, the "court architect" of Pius XI (r. 1922–39), who after 1929 reshaped the new Vatican City. Momo collaborated in the reconstruction with Marcello Piacentini and Attilio Spaccarelli (the designers of via della Conciliazione). The architects moved the palace to an area that, until the mid-19th century, had been occupied by the houses of Soderini, an early Renaissance complex. The accuracy of the reconstruction allows the consideration of the rebuilt Palazzo dei Convertendi not as a new building, but as another phase in the centuries-old life of the edifice.