Rome Patriarchal See

The Rome Patriarchal See is the most venerable of the Christian bishoprics, traditionally founded by Saint Peter, who was martyred in Rome under Nero and buried on the Vatican hill. As the see of the former imperial capital, it stood first among the five patriarchates of the early Church.

Constantine the Great raised a basilica over Peter's tomb between 318 and 322. For twelve centuries Old St. Peter's was the principal shrine of western Christendom: popes were crowned there, and Charlemagne was crowned emperor in it in 800. Saracens sacked the basilica in 846, after which Pope Leo IV enclosed the Vatican with the Leonine Wall.

The see broke communion with Constantinople in the schism of 1054. By the fifteenth century the old church was structurally unsafe; the Renaissance basilica was built from 1506 and consecrated in 1626.