St. Peter's Basilica under construction, Vatican

Tearing down a thousand years to build anew

The original St. Peter's, raised by the emperor Constantine in the fourth century, was crumbling by 1500. In 1506 Pope Julius II took the audacious decision to demolish it and build the largest church in the world in its place.

The foundation stone was laid that year, to a design by Donato Bramante: a vast Greek cross crowned by a dome inspired by the Pantheon. Tearing down the ancient, revered basilica to do it scandalised many, but the work began.

Michelangelo's dome

After Bramante and a string of successors, the 72-year-old Michelangelo was put in charge in 1547.

He simplified the tangled plans and redesigned the dome, raising it far higher and steeper, closer to the soaring profile of Brunelleschi's dome in Florence, to give the building the commanding silhouette it has today. He drove the work for nearly twenty years but died in 1564, before the dome itself was raised.

A century of building

Begun in 1506, St. Peter's was not finished until 1626: one hundred and twenty years.

The dome went up in 1588–1590, just after Michelangelo's death; Bernini's great curving colonnade embracing the piazza came later still. The result became the centre of the Catholic world and remains one of the largest churches ever built. But in 1560 it was, above all, the most ambitious building site on Earth.