This church was dedicated to “San PIETRO” – Saint Peter. Simon, nicknamed Peter (Rock), was a fisherman on the Sea of Galilee when he - together with his brother Andrew - was called by Jesus Christ to be "fishers of men".
According to Catholic understanding, he is the supreme apostle, and the two millennia-long line of popes - currently Francis - are his successor. On statues and paintings, Peter is almost always depicted with two keys in his hand; this attribute refers to the biblical saying in Matthew: “I will give you the keys of the kingdom of heaven; Whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven” (Chapter 16, verse 19).
San Pietro is - together with San Paolo - also known as the "Prince of the Apostles", their common feast day in the saints' calendar is June 29th.