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.
Ferdinando Manlio
From 1540, he led the rebuilding of the Basilica of the Santissima Annunziata Maggiore, along with Giovanni Benincasa. The present church however was rebuilt after a fire destroyed Manlio's building in the 18th century. As a result of this, the viceroy of Naples, Pedro Álvarez de Toledo asked Manlio and Benincasa to design a long road connecting the Royal Palace of Naples to one of the city gates. This is now the via Toledo. The pair also redesigned the Castel Capuano, transforming it from a military building into the new Palace of Justice.