The first church dedicated to St Peter was built at the beginning of the fourth century by Constantine, the first Christian Emperor. It was constructed over what was believed to be the burial place of St Peter, the first bishop of Rome. 

Constantine's church consisted of a nave, four aisles and a narrow transept. It was separated from the piazza by an atrium, which came to be known as the ‘garden of paradise’, because of the beauty of its plants. In the centre was a fountain and in the centre of the fountain was huge bronze pine cone, which dated back to the days of ancient Rome. The pine cone adorns one of the courtyards in the Vatican. The piazza itself was filled with booths and stalls serving and exploiting the needs of the pilgrims.

The interior of the church was sumptuously decorated in gold and silver. Its many precious mosaics were lit by hundreds of candles, which were kept burning before the 52 altars. Below the triumphal arch hung a huge cross between two keys. Beneath this was the Pharos, a colossal candelabra capable of holding over 1,000 candles, which were only lit at Christmas and Easter. Two relics were preserved in chapels: St Peter’s Chair and Veronica’s Veil.

By the 15th century, however, the church was in a parlous state and, in 1452, Pope Nicolas V appointed the Florentine sculptor and architect, Bernardo Rossellino, to remedy the many structural faults. Three years later, however, the pope died and all interest in the project was lost. In 1503, Pope Julius II returned to the project with a vengeance, coming up with the radical idea of building a new church rather mending the old one. No Pope less self-confident than Julius II could have even contemplated the idea of rebuilding one of the most hallowed churches in Christendom. He appointed Donato Bramante as his architect.

The first stone was laid on April 18th, 1506, but the task of rebuilding well over a century. The new St Peter's would not be consecrated until November 18th, 1626. The programme had taken 120 years to complete, during which time 20 popes had died and 10 architects had been consulted.

The interior with its 450 statues, 500 columns and 50 altars is reputed to be able to hold 60,000 people. 

In the first chapel on the right, sits the Basilica's most famous work of art, Michelangelo's 'Pieta'.  it was commissioned, in 1498, by the French Ambassador, Cardinal Jean de Billheres Lagraulas. The work was originally in the French chapel of S. Petronilla, which was attached to the south transept of the old St Peter’s. The hands and feet of Christ are marked with the wounds of the crucifixion. His left foot rests against the stump of a tree, which represents life cut off in its prime. And yet the tree also promises renewed life. The position of Christ draped across his mother's lap recalls the origin of his birth. After the sculpture was attacked on May 21st, 1972, it has been protected by plate glass.

The square in front of the church was designed by Bernini and begun in 1656 and completed in 1667. At its widest point it measures 196m. The colonnade is made up of two rows of two columns, each13m tall, and is surmounted by 140 statues of Saints, Martyrs and Doctors of the church. In the middle of each arm of the colonnade can be seen  coat of arms of Pope Alexander VII, the reigning Pontiff when work first started.

Soaring in the centre of the square is one of Rome's many Egyptian obelisks, which was originally brought to the city by the Emperor Caligula (37-41), in a ship specially built for the purpose. The obelisk was erected a couple of hundred metres from its present site, in the centre of what was then a Circus. (This was where the emperor Nero learnt to race chariots). Ancient tradition maintained that St Peter was martyred at the foot of the obelisk and buried in the adjacent cemetery.

For more information about the obelisks in Rome, see my article: Obelisks