St. Peter's Basilica (Latin: Basilica Sancti Petri), officially known in Italian as Basilica di San Pietro in Vaticano or Basilica Papale di San Pietro, is a Late Renaissance church located within Vatican City.
In Roman Catholic tradition, the basilica is the burial site of its namesake Saint Peter, one of the twelve apostles of Jesus and, also according to tradition, the first Bishop of Rome and therefore first in the line of the papal succession. Tradition and some historical evidence hold that Saint Peter's tomb is directly below the 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 Constantine. Construction of the present basilica, replacing the Old St. Peter's Basilica of the 4th century, began on 18 April 1506 and was completed on 18 November 1626.
Vatican Cityi/ˈvætɨkənˈsɪti/, or Vatican City State, in Italian officially Stato della Città del Vaticano (pronounced [ˈstaːto della t͡ʃitˈta del vatiˈkaːno]), is a landlockedsovereigncity-state whose territory consists of a walled enclave within the city of Rome. It has an area of approximately 44 hectares (110 acres), and a population of just over 800. This makes Vatican City the smallest internationally recognized independent state in the world by both area and population. The current Head of State and Government of the Vatican City State is His Holiness Pope Francis.