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.
Porta del Popolo
The present aspect is the result of a rebuilding carried out in the 16th century, when the gate had again gained a great importance for the urban traffic coming from north. The outer façade was commissioned by Pope Pius IV to Michelangelo, who in turn assigned the task to Nanni di Baccio Bigio: he erected the gate between 1562 and 1565, taking inspiration from the Arch of Titus. The four columns of the façade come from the former St. Peter's Basilica and they frame the single, great archway, overlooked by the stone commemorating the restoration and by the papal coat of arms sustained by two cornucopias; the former circular towers were replaced with two powerful square watchtowers and the whole building was garnished with elegant battlements. In 1638, two statues of St. Peter and St. Paul, sculpted by Francesco Mochi, were inserted between the two pairs of columns: the statues had been rejected by the Basilica of Saint Paul Outside the Walls and given back to the sculptor without payment.