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.
San Giacomo in Augusta
A church at the location was founded along with a hospital by Cardinal Giovanni Colonna in 1339. By 1515, the hospital was in a state of abandon, but within a few decades reopened under the supervision of two religious orders, with the aim of curing those affected by syphilis. Pope Nicholas V placed it under the control of the Company of Santa Maria del Popolo. This order was under the patronage of the Florentine Cardinal Antonio Maria Salviati, and he commissioned the reconstruction of the church. The oval layout of the church at the site was rebuilt starting by Francesco da Volterra in 1592. Upon the former architect's death, the facade and most of the interior decoration completed by Carlo Maderno in 1600.