It seems to be, and is, a gigantic processional canopy. It is here that pilgrims through the centuries have stopped to pray and honor St. Peter.

Above the four, finely carved white marble pedestals adorned with the three bees of the Barberini family crest (Pope Urban VIII, 1568-1644 who commissioned the canopy was a Barberini) rise the spiraling columns.

They are decorated with gold olive and Laurel branches, and graceful little putti. The first part of the columns with helicoidal fluting, typical of Roman tombs symbolizes the soul as it moves heavenward.

Above the columns, weighing a total of 37,000 kgs, is the impressive draping, decorated with festoons that seem to flutter in the breeze.

The white dove in the middle symbolizes the Holy Spirit, and above the capitals, four angels hold wreaths of flowers, while other smaller ones hold the symbols of the papacy: tiara, keys, sword and the Gospel. Above it all is a cross set on a globe, at a height of 29 meters.

It is well known that in creating these columns with their ascending curves, Bernini drew on ancient models. Some sources say that the vine-leaf decorated columns from the old Basilica came from ancient Greece, others say they were from Solomon's Temple in Jerusalem. These eight columns (plus one which is in the Vatican treasure) now decorate the loggia of the reliquiaries that Bernini made in the pillars supporting the dove.

This brilliant project was begun in 1624 and was completed after nine years of intensive work. It is the largest known bronze artwork.