The Vatican Necropolis lies under the Vatican City, at depths varying between 5–12 metres below Saint Peter's Basilica. The Vatican sponsored archaeological excavations under Saint Peter's in the years 1940–1949 which revealed parts of a necropolis dating to the Roman Empire. The work was undertaken at the request of Pope Pius XI who wished to be buried as close as possible to Peter the Apostle. It is also home to the Tomb of the Julii, which has been dated to the third or fourth century.