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 in Porto Basilica
The construction of the new monastery took thirty years and was only completed in 1509, though the canons moved in in 1503. They hosted pope Julius II in the new buildings in 1511 when he was travelling through Romagna - the same year he commissioned Bernardino Tavella to design the canons a new monastery church, but its construction only began in 1553. The roof of the central nave was completed in 1561, but the consecration of the whole church by only occurred on 8 October 1606 - it was presided over by Pietro Aldobrandini, camerlengo and archbishop of Ravenna.