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.
Costa Chapel (Santa Maria del Popolo)
The chapel was originally owned by Domenico della Rovere but it was acquired by Portuguese Cardinal Jorge da Costa (the italianized name is Giorgio Costa) for 200 gold ducats in 1488. Costa was a well-known and influential person in the court of Pope Alexander VI. The Cardinal employed the same workshop of painters as the Della Rovere dynasty, the school of Pinturicchio. It is not unlikely that the patron consciously sought out the same artist. The chapel preserved its original form except one window that was walled up for the creation of a new funeral monument in 1833.