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 reconstruction also had a symbolic message that the evil walnut tree of Nero was supplanted by the beneficent oak of the Della Rovere. The papal coats of arms were placed on the façade and the vaults as "symbols of eternal happiness and protection from lightning", as Landucci explained praising the transposition of the two trees. Another important aspect of the Sistine reconstruction was that it made the basilica – the first church for the pilgrims arriving in Rome from the North – a dynastic monument of the Della Rovere family. This was reinforced by relatives of the pope and other personages of his court who bought chapels and built funeral monuments. "Santa Maria del Popolo became a place to unite visually the universal domination of the church with the della Rovere, a totemic symbol that would associate the della Rovere with Rome and allowed them to co-opt its magnificience and glory", claimed Lisa Passaglia Bauman.