The original St. Peter’s basilica, now referred to as Old St. Peter’s, was built over the site of Saint Peter’s tomb in the fourth century, during the reign of Roman Emperor Constantine. Old St. Peter’s was a basilica-plan church with a long nave, parallel aisles, a narthex, and an apse. Over a thousand years later, in 1506, Pope Julius II boldly decided to completely tear down the deteriorating building, shocking Rome. Imagine deciding to tear down the White House!

Donato Bramante was hired to design the New St. Peter’s. Famous for his design of the Tempietto, Bramante envisioned something similar for St. Peter’s: a central-plan church based on the equidistant forms of a circle and a square. Bramante’s plan was never built, however, as both he and Pope Julius II died. Other great artists, including Raphael, altered Bramante’s plans, and in 1546 Michelangelo became the main architect. He again reworked Bramante’s design, and added a dome. The church was built, though the dome wasn’t completed until after Michelangelo’s death. In the early seventeenth century, the church was redesigned yet again. As it stands now, the plan for New St. Peter’s Basilica looks quite a bit like the original before it was demolished, though the exterior and famous piazza are in the style of the early baroque period.