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, one of Jesus's Apostles and also the first Pope. 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. Peter's Basilica from the 4th century AD, began on 18 April 1506 and was completed on 18 November 1626.
The basilica is cruciform in shape, with an elongated nave in the Latin cross form but the early designs were for a centrally planned structure and this is still in evidence in the architecture. The central space is dominated both externally and internally by one of the largest domes in the world. The entrance is through a narthex, or entrance hall, which stretches across the building. One of the decorated bronze doors leading from the narthex is the Holy Door, only opened during jubilees.
The interior is of vast dimensions when compared with other churches. One author wrote: "Only gradually does it dawn upon us - as we watch people draw near to this or that monument, strangely they appear to shrink; they are, of course, dwarfed by the scale of everything in the building. This in its turn overwhelms us."
