Overview
Michelangelo did not have the satisfaction of seeing it completed: construction of the dome had reached the drum by the time he died in 1564. The work was restarted in 1588 by Giacomo Della Porta and Domenico Fontana and completed in 1589 with the construction of the double-shell dome. Between 1592 and 1605, during the pontificate of Clement VIII, the lantern was completed and the dome was covered with lead plates. In 1593, the large golden bronze sphere surmounted by the cross, by Sebastiano Torrigiani, was placed on the top of the lantern.
Flooded with light and impressive on the inside too, the dome is set on four grandiose arches and as many pillars. In the spandrels, in mosaic, are the evangelists (St Mark and St Matthew based on a design by Cesare Nebbia, while St John and St Luke bear the signature of Giovanni De Vecchi). The six-tier mosaic decoration is by Cavalier d'Arpino (1605). The four large niches at the base of the dome's pillars contain 5-metre-high statues commissioned by Urban VIII (1643). Above them, four ornate balconies by Bernini serve to display the church's most distinguished relics.
You can ascend to the top of the dome from the entrance on the right-hand side of the basilica portico, climbing about 550 steps or covering half of the route with a lift to the terrace roof of the basilica: from here, you have a good view of the dome, the square and the city. Two ramps lead to the circular corridor and the top of the lantern, from where a spiral staircase leads to the external gallery, from which you can admire the splendid panorama of the city as far as the Castelli Romani region and the sea.
