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
In the 15th century the friary of Santa Maria del Popolo joined the observant reform movement that tried to restore the original purity of monastic life. The general chapter of the Augustinian observants in May 1449 established five separate congregations for the observant friars in Italy. That of Rome-Perugia was sometimes named after Santa Maria del Popolo although the monastery never had the official position of a mother-house. In 1472 the friary was given over by Pope Sixtus IV to the Lombard Congregation, the most important and populous of all, and it became its Roman headquarter and the seat of its procurator general (ambassador) at the Roman Curia.