The Papal Basilica of St. Peter in the Vatican, or simply St. Peter's Basilica, is an Italian Renaissance church in Vatican City, the papal enclave within the city of Rome.
Designed principally by Donato Bramante, Michelangelo, Carlo Maderno and Gian Lorenzo Bernini, St. Peter's is the most renowned work of Renaissance architecture and the largest church in the world. While it is neither the mother church of the Catholic Church nor the cathedral of the Diocese of Rome, St. Peter's is regarded as one of the holiest Catholic shrines. It has been described as "holding a unique position in the Christian world" and as "the greatest of all churches of Christendom".
Catholic tradition holds that the Basilica is the burial site of Saint Peter, chief among Jesus's Apostles and also the first Bishop of Rome. Saint Peter's tomb is supposedly directly below the high altar of the Basilica. For this reason, many Popes have been interred at St. Peter's since the Early Christian period, and there has been a church on this site since the time of the Roman emperor Constantine the Great. Construction of the present basilica, which would replace Old St.