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.
Lateran Palace
Two destructive fires, in 1307 and 1361, did irreparable harm, and although vast sums were sent from Avignon for the rebuilding, the palace never again attained its former splendour. The palace had Gothic architectural elements at this point. When the popes returned to Rome they resided first at Basilica di Santa Maria in Trastevere, then at Basilica di Santa Maria Maggiore, and lastly fixed their residence at the Vatican. St. Peter's Basilica, also built by Constantine, had until then served primarily as a pilgrimage church. Sixtus V, more concerned with rationalized urban planning than the preservation of antiquities, then destroyed what still remained of the ancient palace of the Lateran in 1586 preserving only the Sancta Sanctorum, and erected the present much smaller edifice in its place, designed by his favorite architect Domenico Fontana.