This Day in Catholic History | November 18, 1626 St. Peter’s Basilica was completed. Planning began in the 15th Century by Pope Nicholas V and then Pope Julius II, and principal designers were Michelangelo, Donato Bramante, Carlo Maderno, and Gian Lorenzo Bernini. This St. Peter’s Basilica was built to replace the old St. Peter’s Basilica that was built by Constantine the Great in the 4th Century. It’s the largest Catholic Church by interior measure and is one of the greatest works of Renaissanc