This thesis delves into three different fields of study: religion, history, and art history. The purpose is to highlight the impact that religious pilgrimage had on Rome and on the city’s church dedicated to St. Paul. Pilgrimage, during the Middle Ages, played a crucial role in both the artistic and architectural developments at St. Paul’s basilica, San Paolo fuori le mura (St. Paul’s Outside the Walls). While the journey to Rome was the ultimate expression of piety for many pilgrims, not all the early church fathers viewed it as efficacious or necessary. By understanding the arguments raised for and against the pilgrimage to Rome, one is better equipped to assess the motivations for the pilgrims who made the oftentimes dangerous journey. During the Middle Ages, the papacy promoted various practices that created additional motivation for the pilgrims. For instance, the church leaders advocated the cult of the saints and martyrs, disbursed saints’ relics stressing their miracle working powers, and offered indulgences to those who made the journey. By far the most significant method used to encourage pilgrims to come to Rome was the creation the Jubilee Year in 1300 CE, during the pontificate of Boniface VIII. By integrating pilgrimage and indulgences, Boniface flooded Rome with pilgrims. From its original construction through the Medieval Period, St. Paul’s basilica underwent a series of renovations which were focused primarily on its artistic elements. Such projects were typically sanctioned by members of the church and were done in order to accentuate the pilgrim’s experience once they arrived. There is evidence to conclude that the methods employed by the papacy were used in order to highlight Rome’s importance, and, in turn, affected both the art and architecture of St. Paul’s basilica.