Santa Maria del Popolo
Soon after its transfer to the prestigious Lombard Congregation Santa Maria del Popolo was reconstructed between 1472 and 1477 on the orders of Pope Sixtus IV. This was part of the ambitious urban renovation program of the pope who presented himself as "Urbis Restaurator" of Rome. The medieval church was entirely demolished and a new three-aisled, Latin cross shaped basilica was built with four identical chapels on both sides, an octagonal dome above the crossing and a tall Lombard style bell-tower at the end of the right transept. The result of this reconstruction was an early and excellent example of Italian Renaissance architecture in Rome. In spite of the many later changes the basilica essentially kept its Sistine form until today.
Gian Lorenzo Bernini
Bernini was also a leading figure in the emergence of Roman Baroque architecture along with his contemporaries, the architect Francesco Borromini and the painter and architect Pietro da Cortona. Early in their careers they had all worked at the same time at the Palazzo Barberini, initially under Carlo Maderno and, following his death, under Bernini. Later on, however, they were in competition for commissions, and fierce rivalries developed, particularly between Bernini and Borromini. Despite the arguably greater architectural inventiveness of Borromini and Cortona, Bernini's artistic pre-eminence, particularly during the reigns of popes Urban VIII (1623–44) and Alexander VII (1655–65), meant he was able to secure the most important commissions in the Rome of his day, the various massive embellishment projects of the newly finished St. Peter's Basilica, completed under Pope Paul V with the addition of Maderno's nave and facade and finally re-consecrated by Pope Urban VIII on 18 November 1626, after 150 years of planning and building. Bernini's design of the Piazza San Pietro in front of the Basilica is one of his most innovative and successful architectural designs. Within the basilica he is also responsible for the Baldacchino, the decoration of the four piers under the cupola, the Cathedra Petri or Chair of St. Peter in the apse, the chapel of the Blessed Sacrament in the right nave, and the decoration (floor, walls and arches) of the new nave.