The Papal Basilica of St. Peter in the Vatican, or simply St. Peter's Basilica (Latin: Basilica Sancti Petri; Italian: Basilica Papale di San Pietro in Vaticano), is an Italian Renaissance church located 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, according to many, is the largest church in the world. While it is neither the mother church of the Catholic Church nor the Catholic Roman Rite 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". By Catholic tradition, the Basilica is the burial site of its namesake St. Peter, one of the Apostles of Jesus Christ and, also according to tradition, the first Pope and Bishop of Rome. Tradition and strong historical evidence hold that St. Peter's tomb is 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. There has been a church on this site since the time of the Roman Emperor Constantine the Great. Construction of the present basilica, replacing the Old St. Peter's Basilica of the 4th century AD, began on 18 April 1506 and was completed on 18 November 1626.