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.
Santa Maria del Popolo
The dome of Santa Maria del Popolo was the first octagonal Renaissance dome above a rectangular crossing erected on a high tambour. At the time of its building in 1474-75 it had no real precedent, the only comparable examples are the drawings of Filarete for the utopist city of Sforzinda which have never been carried out. As such the dome was a visual anomaly in the skyline of Rome but later became a prototype that has many followers in the city and in other Italian towns. The raison d'être of this novelty was the miraculous icon of Madonna del Popolo that was placed right in the center of the domed sanctuary.