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.
Virginio Vespignani
In 1869, he became the main architect of the Basilica of Saint Paul Outside the Walls. He was professor of architecture at the Academy of Saint Luke, and became president of the institution. He served on many boards and honorary memberships. He helped restore the Papal palace in Anzio. He helped design the layout of the Cemetery of Rome (Campo Verano). He helped design the Palazzo of monsignor Ferrari in Ceprano, the church of Santa Maria in Capranica, and the Palace of Marchese Chino Ferrari in Ceprano. He helped design the New Theaters of Orvieto and of Viterbo. He was responsible for organizing pyrotechnic spectacles and stagepieces for festivals in Castel Sant' Angelo He worked on the restoration of San Lorenzo in Damaso. He has been awarded as knight of the Order of San Silvestro, and that of the Order of Christ of Portugal, or the order of San Gregorio. He receive the Order of the Guadalupe of Mexico, a medal from Emperor Franz Joseph of Austria, Charles the third of Spain. In 1855 the municipality of Rome conferred him a gold medal, for his work during a cholera epidemic.