before all minor basilicas worldwide. However, unlike all the other Papal Major Basilicas, it is wholly within the territory, and thus the sovereign jurisdiction, of the Vatican City State, and not that of Italy. This is in contrast to the other three Papal Major Basilicas, which are within Italian territory and not the territory of the Vatican City State. (Lateran Treaty of 1929, Article 15 (Ibidem)) However, the Holy See fully owns these three basilicas, and Italy is legally obligated to recognize its full ownership thereof (Lateran Treaty of 1929, Article 13 (Ibidem)) and to concede to all of them "the immunity granted by International Law to the headquarters of the diplomatic agents of foreign States" (Lateran Treaty of 1929, Article 15 (Ibidem)). It is the most prominent building in the Vatican City. Its dome is a feature of the skyline of Rome. Probably the largest church in Christendom, it covers an area of . One of the holiest sites of Christianity and Catholic Tradition, it is traditionally the burial site of its titular, St. Peter, who was the head of the twelve Apostles of Jesus and, according to tradition, the first Bishop of Antioch and later the first Bishop of Rome, rendering him the first Pope. Although the New Testament does not mention St. Peter's martyrdom in Rome, tradition, based on the writings of the Fathers of the Church, holds that his tomb is below the baldachin and the altar of the Basilica in the "Confession". For this reason, many Popes have, from the early years of the Church, been buried near Pope St. Peter in the necropolis beneath the Basilica. Construction of the current basilica, over the old Constantinian basilica, began on 18 April 1506 and finished in 1615. At length, on 18 November 1626 Pope Urban VIII solemnly dedicated the Basilica. St. Peter's Basilica is neither the Pope's official seat nor first in rank among the Major Basilicas of Rome. This honour is held by the Pope's cathedral, the Archbasilica of St. John Lateran which is the mother church of all churches in communion with the Catholic Church. However, St. Peter's is certainly the Pope's principal church in terms of use because most Papal liturgies and ceremonies take place there due to its size, proximity to the Papal residence, and location within the Vatican City proper. The "Chair of Saint Peter", or cathedra, an ancient chair sometimes