'You are Peter, and on this rock I will build my church; and the gates of hell shall not prevail against it. And I will give you the keys of the kingdom of heaven; and whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven. (The Bible, Matthew 16:18-19) St. Peter's Church is essential to Christian pilgrimage and is considered the most pious of all churches in Christendom. The reason behind this credibility is clear from the quote above. Christ's injunction here is very evident in regard to Peter's status. “Saint Peter was the chief of the apostles, the first bishop of Rome, who held the keys to heaven” [1], and this is why the church built on the site where he was martyred and cremated plays a major role in making a unique church. of the most influential building and a focal point of the Christian world. The history of the construction of Saint-Pierre is very long and unusual; calling on all the great architects of the time. However, in this essay I will discuss the change in position of the high altar and focus on the contributions of two popes, namely Julius II and Urban VIII, and the architects of their era. This essay will reflect various design choices they made, which ultimately affected the experience of the pilgrimage. Changing the position of the main altar is one of the most crucial steps in making St. Peter's Church the center of Christian pilgrimage. It was Gregory the Great who initiated the change. “The main purpose of this move was to place the altar directly above the saint's tomb to justify the close association of altar and relic developed during the 5th and 6th centuries” [2]. 'The floor of Constantine's apse was raised about 1...... middle of paper ......xford: Oxford University Press, 1999)Webb, Diana. Medieval European pilgrimage, c.700-c.1500. (Basingstoke: Palgrave, 2002.) Wittkower, Rudolf. Gian Lorenzo Bernini: The sculptor of the Roman Baroque. (London: Phaidon Press, 1966).ElectronicMattson, J. 2004. Bernini's work at St. Peter's [online]. Rome. Available at: http://honorsaharchive.blogspot.co.uk/2004/09/berninis-work-at-st-peters.html [Accessed 8 March 2014]. Lecture notes Lawson, J (2014). “Pilgrimage and Vatican: Nicholas V to Paul III”, course notes distributed in the theme ARHI080072014 History of architecture 2b: Culture and city. University of Edinburgh, United Kingdom, January 13. Lawson, J (2014). “Relics and Eucharist: satisfactory end of the journey”, course notes distributed in the theme ARHI080072014 History of architecture 2b: Culture and city. University of Edinburgh, United Kingdom, January 16.